@article{telang_adiabatic_2025,

title = {Adiabatic demagnetization refrigeration with antiferromagnetically ordered NaGdP_{2}O_{7}},

author = {P. Telang and T. Treu and M. Klinger and A. A. Tsirlin and P. Gegenwart and A. Jesche},

url = {https://link.aps.org/doi/10.1103/PhysRevB.111.064431},

doi = {10.1103/PhysRevB.111.064431},

year  = {2025},

date = {2025-02-28},

urldate = {2025-02-01},

journal = {Phys. Rev. B},

volume = {111},

number = {6},

pages = {064431},

keywords = {B3},

pubstate = {published},

tppubtype = {article}

}

@article{wenzel_fermi-liquid_2025,

title = {Fermi-liquid behavior of nonaltermagnetic RuO_{2}},

author = {M. Wenzel and E. Uykur and S. Rößler and M. Schmidt and O. Janson and A. Tiwari and M. Dressel and A. A. Tsirlin},

url = {https://link.aps.org/doi/10.1103/PhysRevB.111.L041115},

doi = {10.1103/PhysRevB.111.L041115},

year  = {2025},

date = {2025-01-28},

urldate = {2025-01-28},

journal = {Phys. Rev. B},

volume = {111},

number = {4},

pages = {L041115},

abstract = {The presence of magnetism in potentially altermagnetic RuO2 has been a subject of intense debate. Using broadband infrared spectroscopy combined with density-functional band-structure calculations, we show that the optical conductivity of RuO2, the bulk probe of its electronic structure, is best described by a nonmagnetic model. The sharp Pauli edge demonstrates the presence of a Dirac nodal line lying 45 meV below the Fermi level. An excellent match between the experimental and ab initio plasma frequencies underpins the weakness of electronic correlations. The intraband part of the optical conductivity indicates Fermi-liquid behavior with two distinct scattering rates below 150 K. Fermi-liquid theory also accounts for the temperature-dependent magnetic susceptibility of RuO2 and allows a consistent description of this material as a paramagnetic metal.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{shen_pressure-dependent_2025,

title = {Pressure-dependent magnetism of the Kitaev candidate Li_{2}RhO_{3}},

author = {B. Shen and Insuasti Pazmino, E. and R. Dhakal and F. Freund and P. Gegenwart and S. M. Winter and A. A. Tsirlin},

url = {https://doi.org/10.1038/s41535-025-00730-1},

doi = {10.1038/s41535-025-00730-1},

year  = {2025},

date = {2025-01-22},

urldate = {2025-01-22},

journal = {npj Quantum Mater.},

volume = {10},

number = {1},

pages = {9},

abstract = {We use magnetization measurements under pressure along with ab initio and cluster many-body calculations to investigate magnetism of the Kitaev candidate Li2RhO3. Hydrostatic compression leads to a decrease in the magnitude of the nearest-neighbor ferromagnetic Kitaev coupling K1 and the corresponding increase in the off-diagonal anisotropy Γ1, whereas the experimental Curie-Weiss temperature changes from negative to positive with the slope of +40 K/GPa. On the other hand, spin freezing persists up to at least 3.46 GPa with the almost constant freezing temperature of 5 K that does not follow the large changes in the exchange couplings and indicates the likely extrinsic origin of spin freezing. Magnetic frustration in Li2RhO3 is mainly related to the interplay between ferromagnetic K1 and antiferromagnetic Γ1, along with the weakness of the third-neighbor coupling J3 that would otherwise stabilize zigzag order. The small J3 distinguishes Li2RhO3 from other Kitaev candidates.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{xu_entanglement_2025,

title = {Entanglement Properties of Gauge Theories from Higher-Form Symmetries},

author = {W. -T. Xu and T. Rakovszky and M. Knap and F. Pollmann},

doi = {10.1103/PhysRevX.15.011001},

year  = {2025},

date = {2025-01-02},

urldate = {2025-01-01},

journal = {Phys. Rev. X},

volume = {15},

number = {1},

pages = {011001},

abstract = {We explore the relationship between higher-form symmetries and entanglement properties in lattice gauge theories with discrete gauge groups, which can exhibit both topologically ordered phases and higher-form symmetry-protected topological (SPT) phases. Our study centers on a generalization of the Fradkin-Shenker model describing ℤ2 lattice gauge theory with matter, where the Gauss law constraint can be either emergent or exact. The phase diagram includes a topologically ordered deconfined phase and a nontrivial SPT phase protected by a 1-form and a 0-form symmetry, among others. We obtain the following key findings: First, the entanglement properties of the model depend on whether the 1-form symmetries and the Gauss law constraint are exact or emergent. For the emergent Gauss law, the entanglement spectrum (ES) of the nontrivial SPT phase exhibits degeneracies, which are robust at low energies against weak perturbations that explicitly break the exact 1-form symmetry. When the Gauss law and the 1-form symmetry are both exact, the ES degeneracy is extensive. This extensive degeneracy turns out to be fragile and can be removed completely by infinitesimal perturbations that explicitly break the exact 1-form symmetry while keeping the Gauss law exact. Second, we consider the ES in the topologically ordered phase where 1-form symmetries are spontaneously broken. In contrast to the ES of the nontrivial SPT phase, we find that spontaneous higher-form symmetry breaking removes “half” of the ES levels, leading to a nondegenerate ES in the topologically ordered phase, in general. Third, we derive a connection between spontaneous higher-form symmetry breaking and the topological entanglement entropy (TEE). Using this relation, we investigate the entanglement entropy that can be distilled in the deconfined phase of the original Fradkin-Shenker model using gauge-invariant measurements. We show that the TEE is robust against the measurement when the 1-form symmetry is emergent but it is fragile when the 1-form symmetry is exact. Our results demonstrate the advantage of higher-form symmetries for understanding entanglement properties of gauge theories.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{tang_crystal_2024,

title = {Crystal field magnetostriction of spin ice under ultrahigh magnetic fields},

author = {N. Tang and M. Gen and M. Rotter and H. Man and K. Matsuhira and A. Matsuo and K. Kindo and A. Ikeda and Y. Matsuda and P. Gegenwart and S. Nakatsuji and Y. Kohama},

url = {https://link.aps.org/doi/10.1103/PhysRevB.110.214414},

doi = {10.1103/PhysRevB.110.214414},

year  = {2024},

date = {2024-12-09},

urldate = {2024-12-01},

journal = {Phys. Rev. B},

volume = {110},

number = {21},

pages = {214414},

abstract = {We present a comprehensive study of the magnetoelastic properties of the Ising pyrochlore oxide Ho2⁢Ti2⁢O7, known as spin ice, by means of high-field magnetostriction measurements and numerical calculations. When a magnetic field is applied along the crystallographic ⟨111⟩ axis, the longitudinal magnetostriction exhibits a broad maximum in the low-field regime around 30 T, followed by a dramatic lattice contraction due to crystal-field (CF) level crossing at 𝐵cf∼65 T. The transverse magnetostriction exhibits a contrasting behavior, highlighting the anisotropic nature of the CF striction. By applying a magnetic field at varying sweep rates, we identify distinct timescales of spin dynamics that are relevant to monopole formation and annihilation, as well as CF-phonon dynamics. Our mean-field calculations, based on a point-charge model, successfully reproduce the overall magnetostriction behavior, revealing the competition between the exchange striction and CF striction. A signature of the CF level crossing is also observed through adiabatic magnetocaloric-effect measurements, consistent with our magnetostriction data.},

keywords = {B3, B5},

pubstate = {published},

tppubtype = {article}

}

@article{abdeldaim_kitaev_2024,

title = {Kitaev Interactions Through an Extended Superexchange Pathway in the j_{eff} = 1/2 Ru^{3+} Honeycomb Magnet RuP_{3}SiO_{11}},

author = {A. H. Abdeldaim and H. Gretarsson and S. J. Day and M. D. Le and G. B. G. Stenning and P. Manuel and R. S. Perry and A. A. Tsirlin and G. J. Nilsen and L. Clark},

doi = {10.1038/s41467-024-53900-3},

year  = {2024},

date = {2024-11-15},

urldate = {2024-11-15},

journal = {Nat. Commun.},

volume = {15},

number = {1},

pages = {9778},

abstract = {Magnetic materials are composed of the simple building blocks of magnetic moments on a crystal lattice that interact via magnetic exchange. Yet from this simplicity emerges a remarkable diversity of magnetic states. Some reveal the deep quantum mechanical origins of magnetism, for example, quantum spin liquid (QSL) states in which magnetic moments remain disordered at low temperatures despite being strongly correlated through quantum entanglement. A promising theoretical model of a QSL is the Kitaev model, composed of unusual bond-dependent exchange interactions, but experimentally, this model is challenging to realise. Here we show that the material requirements for the Kitaev QSL survive an extended pseudo-edge-sharing superexchange pathway of Ru3+ octahedra within the honeycomb layers of the inorganic framework solid, RuP3SiO11. We confirm the requisite 

 state of Ru3+ in RuP3SiO11 and resolve the hierarchy of exchange interactions that provide experimental access to an unexplored region of the Kitaev model.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{kamenskyi_terahertz_2024,

title = {Terahertz Resonant Emission by Optically Excited Infrared-Active Shear Phonons in KY(MoO_{4})_{2}},

author = {D. Kamenskyi and K. Vasin and L. Prodan and K. Kutko and V. Khrustalyov and S. G. Pavlov and H. -W. Hübers},

url = {https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/advs.202407028},

doi = {10.1002/advs.202407028},

year  = {2024},

date = {2024-11-13},

urldate = {2024-11-01},

journal = {Adv. Sci.},

volume = {12},

number = {2},

pages = {2407028},

abstract = {Abstract The generation of monochromatic electromagnetic radiation in the terahertz (THz) frequency range has remained a challenging task for many decades. Here, the emission of monochromatic sub-THz radiation by optical phonons in the dielectric material KY(MoO4)2 is demonstrated. The layered crystal structure of KY(MoO4)2 causes infrared-active shear lattice vibrations to have energies below 3.7 meV, corresponding to frequencies lower than 900 GHz where solid-state-based monochromatic radiation sources are rare. Directly excited by a 5 ps long broadband THz pulse, infrared-active optical vibrations in KY(MoO4)2 re-emit narrowband sub-THz radiation as a time-varying dipole for tens of picoseconds, which is exceptionally long for oscillators with frequencies below 1 THz. Such a long coherent emission allows for the detection of more than 50 periods of radiation with frequencies of 568 and 860 GHz. The remarkably long decay time together with the chemical stability of the employed material suggests a variety of possible applications in THz technology.},

keywords = {C4},

pubstate = {published},

tppubtype = {article}

}

@article{radhakrishnan_imprinted_2024,

title = {Imprinted atomic displacements drive spin–orbital order in a vanadate perovskite},

author = {P. Radhakrishnan and K. S. Rabinovich and A. V. Boris and K. Fürsich and M. Minola and G. Christiani and G. Logvenov and B. Keimer and E. Benckiser},

url = {https://doi.org/10.1038/s41567-024-02686-8},

doi = {10.1038/s41567-024-02686-8},

year  = {2024},

date = {2024-10-29},

urldate = {2024-10-01},

journal = {Nat. Phys.},

volume = {21},

number = {1},

pages = {126},

abstract = {Perovskites with the generic composition ABO3 exhibit an enormous variety of quantum states, such as orbital order, magnetism and superconductivity. Their flexible and comparatively simple structure allows for straightforward chemical substitution and cube-on-cube combination of different compounds in atomically sharp epitaxial heterostructures. Many of the diverse physical properties of perovskites are determined by small deviations from the ideal cubic perovskite structure, which are challenging to control. Here we show that directional imprinting of atomic displacements in the antiferromagnetic Mott insulator YVO3 can be achieved by depositing epitaxial films on different facets of the same isostructural substrate. These facets were chosen such that other well-known control parameters, including lattice and polarity mismatch with the overlayer, remain nearly unchanged. We observe signatures of staggered orbital and magnetic order and demonstrate distinct spin–orbital ordering patterns on different facets. We attribute these results to the influence of specific octahedral rotation and cation displacement patterns, which are imprinted by the substrate facet, on the covalency of the bonds and the superexchange interactions in YVO3. Our results show that substrate-induced templating of lattice distortion patterns constitutes a pathway for materials design beyond established strain-engineering strategies.},

keywords = {B2},

pubstate = {published},

tppubtype = {article}

}

@article{shen_strong_2024,

title = {Strong Enhancement of Magnetic Coercivity Induced by Uniaxial Stress},

author = {B. Shen and F. Breitner and P. Gegenwart and A. Jesche},

doi = {10.1103/PhysRevLett.133.186702},

year  = {2024},

date = {2024-10-28},

urldate = {2024-10-28},

journal = {Phys. Rev. Lett.},

volume = {133},

number = {18},

pages = {186702},

abstract = {The performance of permanent magnets is intricately tied to their magnetic hysteresis loop. In this study, we investigate the heavy-fermion ferromagnet CeAgSb2 through magnetization measurements under uniaxial stress. We observe a 2400% increase in magnetic coercivity with just a modest stress of approximately 1 kbar. This effect persists even after pressure release, attributable to stress-induced defects that efficiently pin domain walls. Other magnetic properties such as ordering temperature and saturation moment exhibit only weak pressure dependencies and display full reversibility. Our findings offer a promising route for increasing coercive field strength and enhancing the energy product in ferromagnetic materials and are potentially applicable to a broad spectrum of commercial or emerging magnetic applications.},

keywords = {B1, B3},

pubstate = {published},

tppubtype = {article}

}

@article{mukharjee_intermediate_2024,

title = {Intermediate field-induced phase of the honeycomb magnet BaCo_{2}(AsO_{4})_{2}},

author = {P. K. Mukharjee and B. Shen and S. Erdmann and A. Jesche and J. Kaiser and P. R. Baral and O. Zaharko and P. Gegenwart and A. A. Tsirlin},

doi = {10.1103/PhysRevB.110.L140407},

year  = {2024},

date = {2024-10-21},

urldate = {2024-10-21},

journal = {Phys. Rev. B},

volume = {110},

number = {14},

pages = {L140407},

abstract = {We use magnetometry, calorimetry, and high-resolution capacitive dilatometry, as well as single-crystal neutron diffraction to explore the temperature-field phase diagram of the anisotropic honeycomb magnet BaCo2⁢(AsO4)2. Our data reveal four distinct ordered states observed for in-plane magnetic fields. Of particular interest is the narrow region between 0.51 and 0.54 T that separates the up-up-down order from the fully polarized state and coincides with the field range where signatures of the spin-liquid behavior have been reported. We show that magnetic Bragg peaks persist in this intermediate phase, thus ruling out its spin-liquid nature. However, the simultaneous nonmonotonic evolution of nuclear Bragg peaks suggests the involvement of the lattice, witnessed also in other regions of the phase diagram where large changes in the sample length are observed upon entering the magnetically ordered states. Our data highlight the importance of lattice effects in BaCo2⁢(AsO4)2.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{birnkammer_signatures_2024,

title = {Signatures of domain-wall confinement in Raman spectroscopy of Ising spin chains},

author = {S. Birnkammer and J. Knolle and M. Knap},

doi = {10.1103/PhysRevB.110.134408},

year  = {2024},

date = {2024-10-03},

urldate = {2024-10-03},

journal = {Phys. Rev. B},

volume = {110},

number = {13},

pages = {134408},

abstract = {Mesonic bound states of domain walls (DWs) can be stabilized in quasi-one-dimensional magnetic compounds. Here, we theoretically study the Raman light scattering response of a twisted Kitaev chain with tilted magnetic fields as a minimal model for confinement in CoNb2⁢O6. By both numerical matrix product states and few-DW variational states, we show that confinement-induced bound states directly manifest themselves as sharp peaks in the Raman response. Remarkably, by tuning the polarization of the incident light field, we demonstrate that the Raman response offers insights into the intrinsic symmetry of the bound-state wave function.},

keywords = {C6},

pubstate = {published},

tppubtype = {article}

}

@article{saubert_evolution_2024,

title = {Evolution of spin dynamics during freezing in the spin-glass Fe_{x}Cr_{1-x}},

author = {S. Säubert and C. Franz and J. K. Jochum and G. Benka and A. Bauer and S. M. Shapiro and P. Böni and C. Pfleiderer},

doi = {10.1103/PhysRevB.110.094422},

year  = {2024},

date = {2024-09-13},

urldate = {2024-09-13},

journal = {Phys. Rev. B},

volume = {110},

number = {9},

pages = {094422},

abstract = {In the iron–chromium system, Fe𝑥⁢Cr1−𝑥, a wide dome of spin-glass behavior emerges when the ferromagnetism of iron is suppressed and the antiferromagnetism of chromium emerges as a function of increasing iron content 𝑥. As both, the high-temperature state and the characteristic cluster size vary as a function of 𝑥, different regimes of spin-glass behavior may be compared in a single, isostructural material system. Here, we report a study of the spin dynamics across the freezing process into the spin-glass state for different iron concentrations (𝑥=0.145, 0.175, 0.21) using modulation of intensity with zero effort (MIEZE) spectroscopy. In the parameter range studied, the relaxation process observed experimentally may be described well in terms of a stretched exponential. In the reentrant cluster-glass regime, 𝑥=0.145, this behavior persists up to high temperatures. In comparison, in the superparamagnetic regime, 𝑥=0.175 and 𝑥=0.21, a single relaxation time at elevated temperatures is observed. For all samples studied, the spin relaxation exhibits a momentum dependence consistent with a power law, providing evidence of a dispersive character of the spin relaxation.},

keywords = {C1, C3},

pubstate = {published},

tppubtype = {article}

}

@article{prodan_anisotropic_2024,

title = {Anisotropic charge transport in the easy-plane kagome ferromagnet Fe_{3}Sn},

author = {L. Prodan and A. Chmeruk and L. Chioncel and V. Tsurkan and I. Kézsmárki},

doi = {10.1103/PhysRevB.110.094407},

year  = {2024},

date = {2024-09-05},

urldate = {2024-09-01},

journal = {Phys. Rev. B},

volume = {110},

number = {9},

pages = {094407},

keywords = {A1, A5},

pubstate = {published},

tppubtype = {article}

}

@article{jin_kinetic_2024,

title = {Kinetic ferromagnetism and topological magnons of the hole-doped Kitaev spin liquid},

author = {H. -K. Jin and W. Kadow and M. Knap and J. Knolle},

doi = {10.1038/s41535-024-00678-8},

year  = {2024},

date = {2024-09-04},

urldate = {2024-09-01},

journal = {npj Quantum Mater.},

volume = {9},

number = {1},

pages = {65},

abstract = {We study the effect of hole doping on the Kitaev spin liquid (KSL) and find that for ferromagnetic (FM) Kitaev exchange K the system is very susceptible to the formation of a FM spin polarization. Through density matrix renormalization group simulations on finite systems, we uncover that the introduction of a single hole, corresponding to ≈1% hole doping for the system size we consider, with a hopping strength of just t textasciitilde 0.28K is enough to disrupt fractionalization and polarize the spins in the [001] direction due to an order-by-disorder mechanism. Taking into account a material relevant FM anisotropic exchange Γ drives the polarization towards the [111] direction via a transition into a topological FM state with chiral magnon excitations. We develop a parton mean-field theory incorporating fermionic holons and bosonic magnons, which accounts for the doping induced FM phases and topological magnon excitations. We discuss experimental implications for Kitaev candidate materials.},

keywords = {C6},

pubstate = {published},

tppubtype = {article}

}

@article{chen_signatures_2024,

title = {Signatures of magnetism control by flow of angular momentum},

author = {L. Chen and Y. Sun and S. Mankovsky and T. N. G. Meier and M. Kronseder and C. Sun and A. Orekhov and H. Ebert and D. Weiss and C. H. Back},

doi = {10.1038/s41586-024-07914-y},

issn = {1476-4687},

year  = {2024},

date = {2024-09-04},

urldate = {2024-09-01},

journal = {Nature},

volume = {633},

number = {8030},

pages = {548–553},

abstract = {Exploring new strategies to manipulate the order parameter of magnetic materials by electrical means is of great importance not only for advancing our understanding of fundamental magnetism but also for unlocking potential applications. A well-established concept uses gate voltages to control magnetic properties by modulating the carrier population in a capacitor structure1–5. Here we show that, in Pt/Al/Fe/GaAs(001) multilayers, the application of an in-plane charge current in Pt leads to a shift in the ferromagnetic resonance field depending on the microwave frequency when the Fe film is sufficiently thin. The experimental observation is interpreted as a current-induced modification of the magnetocrystalline anisotropy ΔHA of Fe. We show that (1) ΔHA decreases with increasing Fe film thickness and is connected to the damping-like torque; and (2) ΔHA depends not only on the polarity of charge current but also on the magnetization direction, that is, ΔHA has an opposite sign when the magnetization direction is reversed. The symmetry of the modification is consistent with a current-induced spin6–8 and/or orbit9–13 accumulation, which, respectively, act on the spin and/or orbit component of the magnetization. In this study, as Pt is regarded as a typical spin current source6,14, the spin current can play a dominant part. The control of magnetism by a spin current results from the modified exchange splitting of the majority and minority spin bands, providing functionality that was previously unknown and could be useful in advanced spintronic devices.},

keywords = {A2},

pubstate = {published},

tppubtype = {article}

}

@article{hemmida_role_2024,

title = {Role of magnetic anisotropy in the antiskyrmion-host schreibersite magnets},

author = {M. Hemmida and J. Masell and K. Karube and D. Ehlers and H. -A. Krug von Nidda and V. Tsurkan and Y. Tokura and Y. Taguchi and I. Kézsmárki},

doi = {10.1103/PhysRevB.110.054416},

year  = {2024},

date = {2024-08-08},

urldate = {2024-08-08},

journal = {Phys. Rev. B},

volume = {110},

number = {5},

pages = {054416},

keywords = {B4},

pubstate = {published},

tppubtype = {article}

}

@article{kirchner_characterizing_2024,

title = {Characterizing the entanglement of anyonic systems using the anyonic partial transpose},

author = {N. Kirchner and W. Choi and F. Pollmann},

doi = {10.1103/PhysRevB.110.085143},

year  = {2024},

date = {2024-08-01},

urldate = {2024-08-01},

journal = {Phys. Rev. B},

volume = {110},

number = {8},

pages = {085143},

abstract = {Entanglement of mixed quantum states can be quantified using the partial transpose and its corresponding entanglement measure, the logarithmic negativity. Recently, the notion of partial transpose has been extended to systems of anyons, which are exotic quasiparticles whose exchange statistics go beyond the bosonic and fermionic cases. Studying the fundamental properties of this anyonic partial transpose, we first reveal that when applied to the special case of fermionic systems, it can be reduced to the fermionic partial transpose or its twisted variant depending on whether or not a boundary Majorana fermion is present. Focusing on ground state properties, we find that the anyonic partial transpose captures both the correct entanglement scaling for gapless systems, as predicted by conformal field theory, and the phase transition between a topologically trivial and a nontrivial phase. For non-Abelian anyons and the bipartition geometry, we find a rich multiplet structure in the eigenvalues of the partial transpose, the so-called negativity spectrum, and reveal the possibility of defining both a charge- and an imbalance-resolved negativity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vasin_optical_2024,

title = {Optical magnetoelectric effect in the polar honeycomb antiferromagnet Fe_{2}Mo_{3}O_{8}},

author = {K. V. Vasin and A. Strinić and F. Schilberth and S. Reschke and L. Prodan and V. Tsurkan and A. R. Nurmukhametov and M. V. Eremin and I. Kézsmárki and J. Deisenhofer},

doi = {10.1103/PhysRevB.110.054401},

year  = {2024},

date = {2024-08-01},

urldate = {2024-08-01},

journal = {Phys. Rev. B},

volume = {110},

number = {5},

pages = {054401},

abstract = {The lack of both time-reversal and spatial inversion symmetry in polar magnets is a prerequisite for the occurrence of optical magnetoelectric effects such as nonreciprocal directional dichroism, i.e., a difference in refractive index and absorption for two counter-propagating electromagnetic waves, which has the potential for the realization of optical diodes. In particular, antiferromagnetic materials with magnetic excitations in the THz range such as Fe2⁢Mo3⁢O8 are promising candidates for next-generation spintronic applications. In a combined experimental and theoretical effort we investigated the THz excitations of the polar honeycomb antiferromagnet Fe2⁢Mo3⁢O8 in external magnetic fields and their nonreciprocal directional dichroism, together with the temperature dependence of the electronic transitions in the mid- and near-infrared frequency range. Using an advanced single-ion approach for the Fe ions, we are able to describe optical excitations from the THz to the near-infrared frequency range quantitatively and model the observed nonreciprocal directional dichroism in the THz regime successfully.},

keywords = {A1, C4},

pubstate = {published},

tppubtype = {article}

}

@article{zerba_realizing_2024,

title = {Realizing topological superconductivity in tunable bose-fermi mixtures with transition metal dichalcogenide heterostructures},

author = {C. Zerba and C. Kuhlenkamp and A. Imamoğlu and M. Knap},

doi = {10.1103/PhysRevLett.133.056902},

year  = {2024},

date = {2024-07-30},

urldate = {2024-07-01},

journal = {Phys. Rev. Lett.},

volume = {133},

number = {5},

pages = {056902},

abstract = {Heterostructures of two-dimensional transition metal dichalcogenides are emerging as a promising platform for investigating exotic correlated states of matter. Here, we propose to engineer Bose-Fermi mixtures in these systems by coupling interlayer excitons to doped charges in a trilayer structure. Their interactions are determined by the interlayer trion, whose spin-selective nature allows excitons to mediate an attractive interaction between charge carriers of only one spin species. Remarkably, we find that this causes the system to become unstable to topological 𝑝+𝑖⁢𝑝 superconductivity at low temperatures. We then demonstrate a general mechanism to develop and control this unconventional state by tuning the trion binding energy using a solid-state Feshbach resonance.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{magnaterra_quasimolecular_2024,

title = {Quasimolecular J_{tet} = 3/2 Moments in the Cluster Mott Insulator GaTa_{4}Se_{8}},

author = {M. Magnaterra and J. Attig and L. Peterlini and M. Hermanns and M. H. Upton and Jungho Kim and L. Prodan and V. Tsurkan and I. Kézsmárki and P. H. M. Loosdrecht and M. Grüninger},

doi = {10.1103/PhysRevLett.133.046501},

year  = {2024},

date = {2024-07-22},

urldate = {2024-07-22},

journal = {Phys. Rev. Lett.},

volume = {133},

number = {4},

pages = {046501},

keywords = {A1},

pubstate = {published},

tppubtype = {article}

}

@article{buttgen_magnetic_2024,

title = {Magnetic resonance in quantum spin chains with competing exchange interactions},

author = {N. Büttgen and H. -A. Krug von Nidda},

doi = {10.1088/1751-8121/ad5e4c},

year  = {2024},

date = {2024-07-18},

urldate = {2024-07-01},

journal = {J. Phys. A: Math. Theor.},

volume = {57},

number = {31},

pages = {313001},

abstract = {Based on a previous review on magnetic resonance in quantum spin chains (Krug von Nidda et al 2010 Eur. Phys. J. Spec. Top. 180 161–89) we report on further development in this field with special focus on transition–metal oxides and halogenides consisting of quasi one–dimensional spin systems, where both intra–and inter–chain exchange interaction may give rise to frustration effects and higher–order anisotropic exchange contributions like the Dzyaloshinskii–Moriya interaction become decisive for the formation of the magnetic ground state. Selected examples show how NMR and ESR contribute valuable information on the magnetic phases and exchange interactions involved: LiCuVO4 with competing nearest neighbour and next–nearest neighbour intra–chain exchange, LiCu2O2 with complex zig–zag chains, and Cs2CuCl4 where the chains form a triangular lattice with the inter–chain interaction weaker but of the same order of magnitude than the intra–chain interaction. The so called paper–chain compound Ba3Cu3In4O12, where each successive pair of CuO4 plaquettes is rotated by 90° with respect to its predecessor along the c–direction like in a paper–chain, provides an interesting topology of frustrated intra–chain exchange interactions. Finally, a few dimer systems are considered.},

keywords = {B4},

pubstate = {published},

tppubtype = {article}

}

@article{kumar_optical_2024,

title = {Optical conductivity of the metallic pyrochlore iridate Pr_{2}Ir_{2}O_{7}: Influence of spin-orbit coupling and electronic correlations on the electronic structure},

author = {H. Kumar and M. Köpf and P. Telang and N. Bura and A. Jesche and P. Gegenwart and C. A. Kuntscher},

url = {https://link.aps.org/doi/10.1103/PhysRevB.110.035140},

doi = {10.1103/PhysRevB.110.035140},

year  = {2024},

date = {2024-07-15},

urldate = {2024-07-01},

journal = {Phys. Rev. B},

volume = {110},

number = {3},

pages = {035140},

abstract = {The synergy of strong spin-orbit coupling and electron-electron interactions gives rise to unconventional topological states, such as topological Mott insulator, Weyl semimetal, and quantum spin liquid. In this study, we have grown single crystals of the pyrochlore iridate Pr2⁡Ir2⁢O7 and explored its magnetic, lattice dynamical, and electronic properties. While Raman spectroscopy data reveal six phonon modes confirming the cubic Fd⁢‾3⁢m crystal symmetry, dc magnetic susceptibility data show no anomalies and hence indicate the absence of magnetic phase transitions down to 2 K. Both temperature-dependent electric transport and optical conductivity data reveal the metallic character of Pr2⁡Ir2⁢O7. The optical conductivity spectrum contains a midinfrared absorption band, which becomes more pronounced with decreasing temperature due to spectral weight transfer from high to low energies. The presence of the midinfrared band hints at the importance of correlation physics. The optical response furthermore suggests that Pr2⁡Ir2⁢O7 is close to the Weyl semimetal phase.},

keywords = {A1, B5},

pubstate = {published},

tppubtype = {article}

}

@article{kalin_influence_2024,

title = {Influence of the magnetovolume effect on the transient reflectivity of MnSi},

author = {J. Kalin and S. Sievers and H. W. Schumacher and H. Füser and M. Bieler and A. Bauer and C. Pfleiderer},

doi = {10.1103/PhysRevB.110.014415},

year  = {2024},

date = {2024-07-11},

urldate = {2024-07-11},

journal = {Phys. Rev. B},

volume = {110},

number = {1},

pages = {014415},

abstract = {The magnetovolume effect is a well established yet frequently overlooked phenomenon in magnetic materials that may affect a wide range of physical properties. Our study explores the influence of the magnetovolume effect on the transient reflectivity of MnSi, a well-known chiral magnet with strong magnetoelastic coupling. We observe a unipolar reflectivity transient in the paramagnetic phase, contrasting with a bipolar response in phases with magnetic long-range order. Comparing our findings with thermal expansion from literature, we establish that the bipolar response originates in the magnetovolume effect which dominates the thermal expansion and influences the optical reflectivity. Our results highlight not only that the magnetovolume effect must be considered when discussing transient reflectivity measurements of magnetic materials but also that such measurements permit to study the characteristic time scales of the magnetovolume effect itself, contributing to a deeper understanding of this often-neglected phenomenon.},

keywords = {C1, C3},

pubstate = {published},

tppubtype = {article}

}

@article{chen_empowering_2024,

title = {Empowering deep neural quantum states through efficient optimization},

author = {A. Chen and M. Heyl},

doi = {10.1038/s41567-024-02566-1},

year  = {2024},

date = {2024-07-01},

urldate = {2024-07-01},

journal = {Nat. Phys.},

volume = {20},

number = {9},

pages = {1476},

abstract = {Computing the ground state of interacting quantum matter is a long-standing challenge, especially for complex two-dimensional systems. Recent developments have highlighted the potential of neural quantum states to solve the quantum many-body problem by encoding the many-body wavefunction into artificial neural networks. However, this method has faced the critical limitation that existing optimization algorithms are not suitable for training modern large-scale deep network architectures. Here, we introduce a minimum-step stochastic-reconfiguration optimization algorithm, which allows us to train deep neural quantum states with up to 106 parameters. We demonstrate our method for paradigmatic frustrated spin-1/2 models on square and triangular lattices, for which our trained deep networks approach machine precision and yield improved variational energies compared to existing results. Equipped with our optimization algorithm, we find numerical evidence for gapless quantum-spin-liquid phases in the considered models, an open question to date. We present a method that captures the emergent complexity in quantum many-body problems through the expressive power of large-scale artificial neural networks.},

keywords = {B6},

pubstate = {published},

tppubtype = {article}

}

@article{pichler_probing_2024,

title = {Probing magnetism in moiré heterostructures with quantum twisting microscopes},

author = {F. Pichler and W. Kadow and C. Kuhlenkamp and M. Knap},

doi = {10.1103/PhysRevB.110.045116},

year  = {2024},

date = {2024-07-01},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {110},

number = {4},

pages = {045116},

abstract = {Spin-ordered states close to metal-insulator transitions are poorly understood theoretically and challenging to probe in experiments. Here, we propose that the quantum twisting microscope, which provides direct access to the energy-momentum resolved spectrum of single-particle and collective excitations, can be used as a novel tool to distinguish between different types of magnetic order. To this end, we calculate the single-particle spectral function and the dynamical spin-structure factor for both a ferromagnetic and antiferromagnetic generalized Wigner crystal formed in fractionally filled moiré superlattices of transition metal dichalcogenide heterostructures. We demonstrate that magnetic order can be clearly identified in these response functions. Furthermore, we explore signatures of quantum phase transitions in the quantum twisting microscope response. We focus on the specific case of triangular moiré lattices at half filling that have been proposed to host a topological phase transition between a chiral spin liquid and a 120° ordered state. Our work demonstrates the potential for quantum twisting microscopes to characterize quantum magnetism in moiré heterostructures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{das_realizing_2024,

title = {Realizing altermagnetism in fermi-hubbard models with ultracold atoms},

author = {P. Das and V. Leeb and J. Knolle and M. Knap},

doi = {10.1103/PhysRevLett.132.263402},

year  = {2024},

date = {2024-06-26},

urldate = {2024-06-01},

journal = {Phys. Rev. Lett.},

volume = {132},

number = {26},

pages = {263402},

abstract = {Altermagnetism represents a type of collinear magnetism, that is in some aspects distinct from ferromagnetism and from conventional antiferromagnetism. In contrast to the latter, sublattices of opposite spin are related by spatial rotations and not only by translations and inversions. As a result, altermagnets have spin-split bands leading to unique experimental signatures. Here, we show theoretically how a 𝑑-wave altermagnetic phase can be realized with ultracold fermionic atoms in optical lattices. We propose an altermagnetic Hubbard model with anisotropic next-nearest neighbor hopping and obtain the Hartree-Fock phase diagram. The altermagnetic phase separates in a metallic and an insulating phase and is robust over a large parameter regime. We show that one of the defining characteristics of altermagnetism, the anisotropic spin transport, can be probed with trap-expansion experiments.},

keywords = {C6},

pubstate = {published},

tppubtype = {article}

}

@article{hirschberger_lattice-commensurate_2024,

title = {Lattice-commensurate skyrmion texture in a centrosymmetric breathing kagome magnet},

author = {M. Hirschberger and B. G. Szigeti and M. Hemmida and M. M. Hirschmann and S. Esser and H. Ohsumi and Y. Tanaka and L. Spitz and S. Gao and K. K. Kolincio and H. Sagayama and H. Nakao and Y. Yamasaki and L. Forró and H. -A. Krug von Nidda and I. Kézsmárki and T. Arima and Y. Tokura},

doi = {10.1038/s41535-024-00654-2},

year  = {2024},

date = {2024-05-23},

urldate = {2024-05-01},

journal = {npj Quantum Mater.},

volume = {9},

pages = {45},

abstract = {Skyrmion lattices (SkL) in centrosymmetric materials typically have a magnetic period on the nanometer-scale, so that the coupling between magnetic superstructures and the underlying crystal lattice cannot be neglected. We reveal the commensurate locking of a SkL to the atomic lattice in Gd3Ru4Al12 via high-resolution resonant elastic x-ray scattering (REXS). Weak easy-plane magnetic anisotropy, demonstrated here by a combination of ferromagnetic resonance and REXS, penalizes placing a skyrmion core on a site of the atomic lattice. Under these conditions, a commensurate SkL, locked to the crystal lattice, is stable at finite temperatures – but gives way to a competing incommensurate ground state upon cooling. We discuss the role of Umklapp-terms in the Hamiltonian for the formation of this lattice-locked state, its magnetic space group, and the role of slight discommensurations, or (line) defects in the magnetic texture. We also contrast our findings with the case of SkLs in noncentrosymmetric material platforms.},

keywords = {B4, B5},

pubstate = {published},

tppubtype = {article}

}

@article{matsumoto_quantum_2024,

title = {A quantum critical Bose gas of magnons in the quasi-two-dimensional antiferromagnet YbCl_{3} under magnetic fields},

author = {Y. Matsumoto and S. Schnierer and J. A. N. Bruin and J. Nuss and P. Reiss and G. Jackeli and K. Kitagawa and H. Takagi},

url = {https://doi.org/10.1038/s41567-024-02498-w},

doi = {10.1038/s41567-024-02498-w},

year  = {2024},

date = {2024-05-09},

urldate = {2024-05-09},

journal = {Nat. Phys.},

volume = {20},

number = {7},

pages = {1131–1138},

abstract = {Bose–Einstein condensation (BEC) is a quantum phenomenon in which a macroscopic number of bosons occupy the lowest energy state and acquire coherence at low temperatures. In three-dimensional antiferromagnets, a magnetic-field-induced transition has been successfully described as a magnon BEC. For a strictly two-dimensional (2D) system, it is known that BEC cannot take place due to the presence of a finite density of states at zero energy. However, in a realistic quasi-2D magnet consisting of stacked magnetic layers, a small but finite interlayer coupling stabilizes marginal BEC but such that 2D physics is still expected to dominate. This 2D-limit BEC behaviour has been reported in a few materials but only at very high magnetic fields that are difficult to access. The honeycomb S = 1/2 Heisenberg antiferromagnet YbCl3 exhibits a transition to a fully polarized state at a relatively low in-plane magnetic field. Here, we demonstrate the formation of a quantum critical 2D Bose gas at the transition field, which, with lowering the field, experiences a BEC marginally stabilized by an extremely small interlayer coupling. Our observations establish YbCl3, previously a Kitaev quantum spin liquid material, as a realization of a quantum critical BEC in the 2D limit.},

keywords = {A3},

pubstate = {published},

tppubtype = {article}

}

@article{kunze_optical_2024,

title = {Optical signatures of type-II Weyl fermions in the noncentrosymmetric semimetals RAlSi (R = La, Ce, Pr, Nd, Sm)},

author = {J. Kunze and M. Köpf and W. Cao and Y. Qi and C. A. Kuntscher},

url = {https://link.aps.org/doi/10.1103/PhysRevB.109.195130},

doi = {10.1103/PhysRevB.109.195130},

year  = {2024},

date = {2024-05-09},

urldate = {2024-05-09},

journal = {Phys. Rev. B},

volume = {109},

number = {19},

pages = {195130},

abstract = {Weyl semimetals with magnetic ordering provide a promising platform for the investigation of rare topological effects such as the anomalous Hall effect, resulting from the interplay of nontrivial bands with various spin configurations. The materials RAlSi, where R represents a rare-earth element, are prominent representatives of Weyl semimetals, where the Weyl states are induced by space inversion symmetry breaking, and in addition, for several rare-earth elements R, enhanced by time-reversal symmetry breaking through the formation of a magnetic order at low temperature. We report optical signatures of Weyl fermions in the magnetic compounds CeAlSi, PrAlSi, NdAlSi, and SmAlSi as well as the nonmagnetic family member LaAlSi by broad-frequency infrared spectroscopy at room temperature, i.e., in the paramagnetic phase. A similar profile of the optical conductivity spectrum and a metallic character are observed for all compounds, with LaAlSi showing the strongest free charge-carrier contribution. Furthermore, the linear-in-frequency behavior of the optical conductivity of all investigated compounds indicates the presence of Weyl nodes in close proximity to the Fermi energy, resulting from inversion symmetry breaking in noncentrosymmetric structures. According to the characteristics of these linear slopes, the RAlSi compounds are expected to host mainly type-II Weyl states with overtilted Weyl cones. The results are compared to the optical response of the closely related RAlGe materials, which are considered as potential hybridization-driven Weyl-Kondo systems.},

keywords = {A1},

pubstate = {published},

tppubtype = {article}

}

@article{reinhoffer_strong_2024,

title = {Strong Terahertz Third-Harmonic Generation by Kinetic Heavy Quasiparticles in CaRuO_{3}},

author = {C. Reinhoffer and S. Esser and S. Esser and E. Mashkovich and S. Germanskiy and P. Gegenwart and F. Anders and P. H. M. Loosdrecht and Z. Wang},

url = {https://link.aps.org/doi/10.1103/PhysRevLett.132.196501},

doi = {10.1103/PhysRevLett.132.196501},

year  = {2024},

date = {2024-05-08},

urldate = {2024-05-08},

journal = {Phys. Rev. Lett.},

volume = {132},

number = {19},

pages = {196501},

abstract = {We report on time-resolved nonlinear terahertz spectroscopy of a strongly correlated ruthenate, CaRuO_{3}, as a function of temperature, frequency, and terahertz field strength. Third-harmonic radiation for frequencies up to 2.1 THz is observed evidently at low temperatures below 80 K, where the low-frequency linear dynamical response deviates from the Drude model and a coherent heavy quasiparticle band emerges by strong correlations associated with the Hund’s coupling. Phenomenologically, by taking an experimentally observed frequency-dependent scattering rate, the deviation of the field driven kinetics from the Drude behavior is reconciled in a time-dependent Boltzmann description, which allows an attribution of the observed third-harmonic generation to the terahertz field driven nonlinear kinetics of the heavy quasiparticles.},

keywords = {B1, B5},

pubstate = {published},

tppubtype = {article}

}

@article{ebad-allah_optical_2024,

title = {Optical anisotropy of the kagome magnet FeSn: Dominant role of excitations between kagome and Sn layers},

author = {J. Ebad-Allah and M. -C. Jiang and R. Borkenhagen and F. Meggle and L. Prodan and V. Tsurkan and F. Schilberth and G. -Y. Guo and R. Arita and I. Kézsmárki and C. A. Kuntscher},

doi = {10.1103/PhysRevB.109.L201106},

year  = {2024},

date = {2024-05-07},

urldate = {2024-05-01},

journal = {Phys. Rev. B},

volume = {109},

number = {20},

pages = {L201106},

abstract = {Antiferromagnetic FeSn is considered to be a close realization of the ideal two-dimensional (2D) kagome lattice, hosting Dirac cones, van Hove singularities, and flat bands, as it comprises Fe3Sn kagome layers well separated by Sn buffer layers. We observe a pronounced optical anisotropy, with the low-energy optical conductivity being surprisingly higher perpendicular to the kagome planes than along the layers. This finding contradicts the prevalent picture of dominantly 2D electronic structure for FeSn. Our material-specific theory reproduces the measured conductivity spectra remarkably well. A site-specific decomposition of the optical response to individual excitation channels shows that the optical conductivity for polarizations both parallel and perpendicular to the kagome plane is dominated by interlayer transitions between kagome layers and adjacent Sn-based layers. Moreover, the matrix elements corresponding to these transitions are highly anisotropic, leading to larger out-of-plane conductivity. Our results evidence the crucial role of interstitial layers in charge dynamics even in seemingly 2D systems.},

keywords = {A1},

pubstate = {published},

tppubtype = {article}

}

@article{huber_fermi_2024,

title = {Fermi surface of the chiral topological semimetal CoSi},

author = {N. Huber and S. Mishra and I. Sheikin and K. Alpin and A. P. Schnyder and G. Benka and A. Bauer and C. Pfleiderer and M. A. Wilde},

doi = {10.1103/PhysRevB.109.205115},

year  = {2024},

date = {2024-05-06},

urldate = {2024-05-01},

journal = {Phys. Rev. B},

volume = {109},

number = {20},

pages = {205115},

abstract = {We report a study of the Fermi surface of the chiral semimetal CoSi and its relationship to a network of multifold topological crossing points, Weyl points, and topological nodal planes in the electronic band structure. Combining quantum oscillations in the Hall resistivity, magnetization, and torque magnetization with ab initio electronic structure calculations, we identify two groups of Fermi-surface sheets, one centered at the 𝑅 point and the other centered at the Γ point. The presence of topological nodal planes at the Brillouin zone boundary enforces topological protectorates on the Fermi-surface sheets centered at the 𝑅 point. In addition, Weyl points exist close to the Fermi-surface sheets centered at the 𝑅 and the Γ points. In contrast, topological crossing points at the 𝑅 point and the Γ point, which have been advertised to feature exceptionally large Chern numbers, are located at a larger distance to the Fermi level. Representing a unique example in which the multitude of topological band crossings has been shown to form a complex network, our observations in CoSi highlight the need for detailed numerical calculations of the Berry curvature at the Fermi level, regardless of the putative existence and the possible character of topological band crossings in the band structure.},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{kosior_vortex_2024,

title = {Vortex loop dynamics and dynamical quantum phase transitions in three-dimensional fermion matter},

author = {A. Kosior and M. Heyl},

doi = {10.1103/physrevb.109.l140303},

year  = {2024},

date = {2024-04-15},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {14},

pages = {L140303},

abstract = {Over the past decade, dynamical quantum phase transitions (DQPTs) have emerged as a paradigm shift in understanding nonequilibrium quantum many-body systems. However, the challenge lies in identifying order parameters that effectively characterize the associated dynamic phases. In this study we investigate the behavior of vortex singularities in the phase of the Green's function for a broad class of fermion lattice models in three dimensions after an instantaneous quench in both interacting and noninteracting systems. We find that the full set of vortices form one-dimensional dynamical objects, which we call vortex loops. We propose that the number of such vortex loops can be interpreted as a quantized order parameter that distinguishes between different nonequilibrium phases. Our results establish an explicit link between variations in the order parameter and DQPTs in the noninteracting scenario. Moreover, we show that the vortex loops are robust in the weakly interacting case, even though there is no direct relation between the Loschmidt amplitude and the Green's function. Finally, we observe that vortex loops can form complex dynamical patterns in momentum space. Our findings provide valuable insights for developing definitions of dynamical order parameters in nonequilibrium systems.},

keywords = {B6},

pubstate = {published},

tppubtype = {article}

}

@article{luo_probing_2024,

title = {Probing off-diagonal eigenstate thermalization with tensor networks},

author = {M. Luo and R. Trivedi and M. C. Bañuls and J. I. Cirac},

doi = {10.1103/PhysRevB.109.134304},

year  = {2024},

date = {2024-04-08},

urldate = {2024-04-01},

journal = {Phys. Rev. B},

volume = {109},

number = {13},

pages = {134304},

keywords = {C5},

pubstate = {published},

tppubtype = {article}

}

@article{boesl_deconfinement_2024,

title = {Deconfinement Dynamics of Fractons in Tilted Bose-Hubbard Chains},

author = {J. Boesl and P. Zechmann and J. Feldmeier and M. Knap},

doi = {10.1103/PhysRevLett.132.143401},

year  = {2024},

date = {2024-04-01},

urldate = {2023-01-01},

journal = {Phys. Rev. Lett.},

volume = {132},

number = {14},

pages = {143401},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{jones_superconducting_2024,

title = {Superconducting transition temperatures of pure vanadium and vanadium-titanium alloys in the presence of dynamical electronic correlations},

author = {D. Jones and A. Östlin and A. Weh and F. Beiuşeanu and U. Eckern and L. Vitos and L. Chioncel},

doi = {10.1103/PhysRevB.109.165107},

year  = {2024},

date = {2024-04-01},

urldate = {2024-04-12},

journal = {Phys. Rev. B},

volume = {109},

number = {16},

pages = {165107},

abstract = {Ordinary superconductors are widely assumed insensitive to small concentrations of random nonmagnetic impurities, whereas strong disorder suppresses superconductivity, ultimately leading to a superconductor-insulator transition. In between these limiting cases, a most fascinating regime may emerge where disorder enhances superconductivity. This effect is discussed here for the β phase of vanadium-titanium alloys. Disorder is modeled using the coherent potential approximation while local electronic interactions are treated using dynamical mean-field theory. The McMillan formula is employed to estimate the superconducting transition temperature, showing a maximum at a Ti concentration of around 0.33 for a local Coulomb interaction U in the range of 2 eV to 3 eV. Our calculations quantitatively agree with the experimentally observed concentration-dependent increase of Tc, and its maximal value of about 20%.},

keywords = {A5},

pubstate = {published},

tppubtype = {article}

}

@article{solana-madruga_covo_3_2023,

title = {CoVO_{3} High-Pressure Polymorphs: To Order or Not to Order?},

author = {E. Solana-Madruga and O. Mentre and A. A. Tsirlin and M. Huve and D. Khalyavin and C. Ritter and A. M. Arevalo-Lopez},

doi = {10.1002/advs.202307766},

year  = {2024},

date = {2024-03-06},

urldate = {2023-12-01},

journal = {Adv. Sci.},

volume = {11},

number = {9},

pages = {2307766},

abstract = {Materials properties are determined by their compositions and structures. In ABO(3) oxides different cation orderings lead to mainly perovskite- or corundum like derivatives with exciting physical properties. Sometimes, a material can be stabilized in more than one structural modification, providing a unique opportunity to explore structure-properties relationship. Here, CoVO3 obtained in both ilmenite-(CoVO3-I) and LiNbO3-type (CoVO3-II) polymorphs at moderate (8-12 GPa) and high pressures (22 GPa), respectively are presented. Their distinctive cation distributions affect drastically the magnetic properties as CoVO3-II shows a cluster-glass behavior while CoVO3-I hosts a honeycomb zigzag magnetic structure in the cobalt network. First principles calculations show that the influence of vanadium is crucial for CoVO3-I, although it is previously considered as non-magnetic in a dimerized spin-singlet state. Contrarily, CoVO3-II shows two independent interpenetrating antiferromagnetic Co- and ferromagnetic V-hcp sublattices, which intrinsically frustrate any possible magnetic order. CoVO3-II is also remarkable as the first oxide crystallizing with the LiNbO3-type structure where both metals contain free d electrons. CoVO3 polymorphs pinpoint therefore as well to a much broader phase field of high-pressure A-site Cobaltites.},

keywords = {B1, B3},

pubstate = {published},

tppubtype = {article}

}

@article{zechmann_dynamical_2024,

title = {Dynamical Spectral Response of Fractonic Quantum Matter},

author = {P. Zechmann and J. Boesl and J. Feldmeier and M. Knap},

doi = {10.1103/physrevb.109.125137},

year  = {2024},

date = {2024-03-01},

journal = {Phys. Rev. B},

volume = {109},

number = {12},

pages = {125137},

abstract = {Quantum many-body systems with fractonic excitations can realize fascinating phases of matter. Here, we study the low-energy excitations of a constrained Bose-Hubbard model in one dimension, which conserves the center of mass or, equivalently, the dipole moment in addition to the particle number. This model is known to realize fractonic phases, including a dipole Mott insulator, a dipole Luttinger liquid, and a metastable dipole supersolid. We use tensor network methods to compute spectral functions from the dynamical response of the system and verify predictions from low-energy field theories of the corresponding ground-state phases. We demonstrate the existence of gapped excitations compatible with strong coupling results in a dipole Mott insulator, linear sound modes characteristic of a Luttinger liquid of dipoles, and soft quadratic modes at both zero and finite momenta in a supersolid state with charge density wave order and phase coherence at noninteger filling.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{choi_finite_2024,

title = {Finite Temperature Entanglement Negativity of Fermionic Symmetry Protected Topological Phases and Quantum Critical Points in One Dimension},

author = {W. Choi and M. Knap and F. Pollmann},

doi = {10.1103/PhysRevB.109.115132},

year  = {2024},

date = {2024-03-01},

urldate = {2023-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {11},

pages = {115132},

keywords = {C5},

pubstate = {published},

tppubtype = {article}

}

@article{dornellas_kitaev-heisenberg_2024,

title = {Kitaev-Heisenberg model on the star lattice: From chiral Majorana fermions to chiral triplons},

author = {P. d'Ornellas and J. Knolle},

doi = {10.1103/PhysRevB.109.094421},

year  = {2024},

date = {2024-03-01},

urldate = {2024-04-12},

journal = {Phys. Rev. B},

volume = {109},

number = {9},

pages = {094421},

abstract = {The interplay of frustrated interactions and lattice geometry can lead to a variety of exotic quantum phases. Here we unearth a particularly rich phase diagram of the Kitaev-Heisenberg model on the star lattice, a triangle decorated honeycomb lattice breaking sublattice symmetry. In the antiferromagnetic regime, the interplay of Heisenberg coupling and geometric frustration leads to the formation of valence bond solid (VBS) phases—a singlet VBS and a bond selective triplet VBS stabilized by the Kitaev exchange. We show that the ratio of the Kitaev versus Heisenberg exchange tunes between these VBS phases and chiral quantum spin-liquid regimes. Remarkably, the VBS phases host a whole variety of chiral triplon excitations with high Chern numbers in the presence of a weak magnetic field. We discuss our results in light of a recently synthesized star lattice material and other decorated lattice systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{shen_magnetic_2024,

title = {Magnetic vs. nonmagnetic polymorphs of RuBr_{3} under pressure},

author = {B. Shen and V. A. Ginga and A. M. Arévalo-López and G. Garbarino and E. Uykur and M. Goncalves-Faria and P. K. Mukharjee and P. Gegenwart and A. A. Tsirlin},

doi = {10.1103/PhysRevB.109.224402},

year  = {2024},

date = {2024-03-01},

urldate = {2024-03-01},

journal = {Phys. Rev. B},

volume = {109},

number = {22},

pages = {224402},

abstract = {Pressure evolution of the crystal structure and magnetism of the honeycomb 𝛼-RuBr_3 is studied using high-pressure x-ray diffraction, magnetometry, and density-functional band-structure calculations. Hydrostatic compression transforms antiferromagnetic 𝛼-RuBr_3 (R-3) into paramagnetic 𝛼'-RuBr_3 (P-1) where short Ru-Ru bonds cause magnetism collapse above 1.3 GPa at 0 K and 2.5 GPa at 295 K. Below this critical pressure, the Ntextbackslash'eel temperature of 𝛼-RuBr_3 increases with the slope of 1.8 K/GPa. Pressure tunes 𝛼-RuBr_3 away from the Kitaev limit, whereas increased third-neighbor in-plane coupling and interlayer coupling lead to a further stabilization of the collinear zigzag state. Both 𝛼- and 𝛼'-RuBr_3 are metastable at ambient pressure, but their transformation into the thermodynamically stable 𝛽-polymorph is kinetically hindered at room temperature.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{wang_spin-orbit_2024,

title = {Spin-Orbit Excitons in a Correlated Metal: Raman Scattering Study of Sr_{2}RhO_{4}},

author = {L. Wang and H. Liu and V. Zimmermann and A. K. Yogi and M. Isobe and M. Minola and M. Hepting and G. Khaliullin and B. Keimer},

doi = {10.1103/PhysRevLett.132.116502},

year  = {2024},

date = {2024-03-01},

urldate = {2024-03-01},

journal = {Phys. Rev. Lett.},

volume = {132},

number = {11},

pages = {116502},

abstract = {Using Raman spectroscopy to study the correlated 4d-electron metal Sr2RhO4, we observe pronounced excitations at 220 meV and 240 meV with A1g and B1g symmetries, respectively. We identify them as transitions between the spin-orbit multiplets of the Rh ions, in close analogy to the spin-orbit excitons in the Mott insulators Sr2IrO4 and α−RuCl3. This observation provides direct evidence for the unquenched spin-orbit coupling in Sr2RhO4. A quantitative analysis of the data reveals that the tetragonal crystal field Δ in Sr2RhO4 has a sign opposite to that in insulating Sr2IrO4, which enhances the planar xy orbital character of the effective J=1/2 wave function. This supports a metallic ground state, and suggests that c-axis compression of Sr2RhO4 may transform it into a quasi-two-dimensional antiferromagnetic insulator.},

keywords = {B2},

pubstate = {published},

tppubtype = {article}

}

@article{muller_chiral_2024,

title = {Chiral phonons and phononic birefringence in ferromagnetic metal–bulk acoustic resonator hybrids},

author = {M. Müller and J. Weber and F. Engelhardt and V. A. S. V. Bittencourt and T. Luschmann and M. Cherkasskii and M. Opel and S. T. B. Goennenwein and S. V. Kusminskiy and S. Geprägs and R. Gross and M. Althammer and H. Huebl},

doi = {10.1103/PhysRevB.109.024430},

year  = {2024},

date = {2024-01-23},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {2},

pages = {024430},

abstract = {Magnomechanical devices, in which magnetic excitations couple to mechanical vibrations, have been discussed as efficient and broadband microwave signal transducers in the classical and quantum limit. We experimentally investigate the resonant magnetoelastic coupling between the ferromagnetic resonance modes in metallic Co25Fe75 thin films, featuring ultralow magnetic damping as well as sizable magnetostriction, and standing transverse elastic phonon modes in sapphire, silicon, and gadolinium gallium garnet at cryogenic temperatures. For all substrates, we observe a coherent interaction between the acoustic and magnetic modes. We identify the phonon modes as transverse shear waves propagating with slightly different velocities (Δv/v≃10−5); i.e., all investigated substrates show potential for phononic birefringence as well as phonon-mediated angular momentum transport. Our magnon-phonon hybrid systems operate in a coupling regime analogous to the Purcell enhanced damping in cavity magnonics.},

keywords = {C3},

pubstate = {published},

tppubtype = {article}

}

@article{wu_crossover_2024,

title = {Crossover between electron-electron and electron-phonon mediated pairing on the Kagome lattice},

author = {X. Wu and D. Chakraborty and A. P. Schnyder and A. Greco},

doi = {10.1103/physrevb.109.014517},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {1},

pages = {014517},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{romen_deconfined_2024,

title = {Deconfined quantum criticality in the long-range, anisotropic Heisenberg chain},

author = {A. Romen and S. Birnkammer and M. Knap},

doi = {10.21468/scipostphyscore.7.1.008},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {SciPost Phys. Core},

volume = {7},

number = {1},

pages = {008},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{zhao_discrete_2024,

title = {Discrete degeneracies distinguished by the anomalous Hall effect in a metallic kagome ice compound},

author = {K. Zhao and Y. Tokiwa and H. Chen and P. Gegenwart},

doi = {10.1038/s41567-023-02307-w},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Nat. Phys.},

volume = {20},

pages = {442},

abstract = {In magnetic crystals, despite the explicit breaking of time-reversal symmetry, two equilibrium states related by time reversal are always energetically degenerate. In ferromagnets, this time-reversal degeneracy is reflected in the hysteresis of the magnetic field dependence of the magnetization and, if metallic, in that of the anomalous Hall effect (AHE). Under time-reversal, both these quantities change signs but not their magnitude. Here we show that a time-reversal-like degeneracy appears in the metallic kagome spin ice HoAgGe when magnetic fields are applied parallel to the kagome plane. We find vanishing hysteresis in the field dependence of the magnetization at low temperature, but finite hysteresis in the field-dependent AHE. This suggests the emergence of states with nearly the same energy and net magnetization but different sizes of the AHE and of the longitudinal magnetoresistance. By analysing the experimental data and a minimal tight-binding model, we identify a time-reversal-like operation connecting these near-degenerate states, which is related to the non-trivial distortion of the kagome lattice in HoAgGe. Our work demonstrates the diagnostic power of transport phenomena for identifying hidden symmetries in frustrated spin systems. Transport measurements of the metallic kagome spin ice HoAgGe show that it has an emergent discrete symmetry that is not apparent from measurements of its magnetization.},

keywords = {B3},

pubstate = {published},

tppubtype = {article}

}

@article{kutko_high-field_2024,

title = {High-field magnetization of KEr(MoO_{4})_{2}},

author = {K. Kutko and B. Bernáth and V. Khrustalyov and O. Young and H. Engelkamp and P. C. M. Christianen and L. Prodan and Y. Skourski and L. V. Pourovskii and S. Khmelevskyi and D. Kamenskyi},

doi = {10.1103/PhysRevB.109.024438},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {2},

pages = {024438},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{leeb_interband_2024,

title = {Interband scattering-and nematicity-induced quantum oscillation frequency in FeSe},

author = {V. Leeb and J. Knolle},

doi = {10.1103/physrevb.109.l081109},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {8},

pages = {L081109},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hu_phonon_2024,

title = {Phonon promoted charge density wave in topological kagome metal ScV_{6}Sn_{6}},

author = {Y. Hu and J. Ma and Y. Li and Y. Jiang and D. J. Gawryluk and T. Hu and J. Teyssier and V. Multian and Z. Yin and S. Xu and others},

doi = {10.1038/s41467-024-45859-y},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Nat. Commun.},

volume = {15},

number = {1},

pages = {1658},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{simeth_topological_2024,

title = {Topological aspects of multi-k antiferromagnetism in cubic rare-earth compounds},

author = {W. Simeth and M. C. Rahn and A. Bauer and M. Meven and C. Pfleiderer},

doi = {10.1088/1361-648x/ad24bb},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {J. Phys.: Condens. Matter},

volume = {36},

number = {21},

pages = {215602},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{panther_frustration_2023,

title = {Frustration relief and reorientation transition in the kagomelike dolerophanite Cu_{2}OSO_{4}},

author = {A. Panther and A. A. Tsirlin and I. Rousochatzakis},

doi = {10.1103/PhysRevB.108.224410},

year  = {2023},

date = {2023-12-01},

urldate = {2023-12-01},

journal = {Phys. Rev. B},

volume = {108},

number = {22},

pages = {224410},

abstract = {We present a theoretical study of dolerophanite Cu2OSO4, a layered kagomelike spin-21 magnetic insulator that can be described either as a system of chains coupled through dimers or as a kagome lattice where every third spin is replaced by a ferromagnetic spin dimer. Building on insights from ab initio calculations, classical numerical minimizations, and semiclassical expansions, we arrive at a minimal microscopic description that accounts for the experimental data reported so far, including the nature of the magnetic order, the reported spin length, and the observed anisotropy. The latter arises by a peculiar competition between the antisymmetric (DzyaloshinskiiMoriya) and the symmetric part of the exchange anisotropy, which gives rise to a two-step reorientation process involving two successive continuous phase transitions. In this paper, we uncover mechanisms stabilizing canted ferrimagnetic order in kagome systems and highlight strong magnetic anisotropy in the presence of dissimilar magnetic orbitals on crystallographically nonequivalent Cu sites. We also show how these anisotropy terms affect the spin-wave spectrum and how they can be tracked experimentally.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{breitner_metallic_2023,

title = {Metallic conductivity in Na-deficient structural domain walls in the spin-orbit Mott insulator Na_{2}IrO_{3}},

author = {F. A. Breitner and J. Kaiser and A. Jesche and P. Gegenwart},

doi = {10.1103/PhysRevB.108.235130},

year  = {2023},

date = {2023-12-01},

urldate = {2023-12-01},

journal = {Phys. Rev. B},

volume = {108},

number = {23},

pages = {235130},

abstract = {Honeycomb Na2IrO3 is a prototype spin-orbit Mott insulator and Kitaev magnet. We report a combined structural and electrical resistivity study of Na2IrO3 single crystals. Laue back-scattering diffraction indicates twinning with +/- 120 degrees rotation around the c* axis while scanning electron microscopy displays nanothin lines parallel to all three b-axis orientations of twin domains. Energy dispersive x-ray analysis line scans across such domain walls indicate no change of the Ir signal intensity, i.e., intact honeycomb layers, while the Na intensity is reduced down to similar to 2/3 of its original value at the domain walls, implying significant hole doping. Utilizing focused-ion-beam microsectioning, the temperature dependence of the electrical resistance of individual domain walls is studied. It demonstrates the tuning through the metal-insulator transition into a correlated-metal ground state by increasing hole doping.},

keywords = {B1},

pubstate = {published},

tppubtype = {article}

}

@article{alpin_fundamental_2023,

title = {Fundamental laws of chiral band crossings: Local constraints, global constraints, and topological phase diagrams},

author = {K. Alpin and M. M. Hirschmann and N. Heinsdorf and A. Leonhardt and W. Y. Yau and X. Wu and A. P. Schnyder},

doi = {10.1103/PhysRevResearch.5.043165},

year  = {2023},

date = {2023-11-01},

urldate = {2023-11-01},

journal = {Phys. Rev. Research},

volume = {5},

number = {4},

pages = {043165},

abstract = {We derive two fundamental laws of chiral band crossings: (i) a local constraint relating the Chern number to phase jumps of rotation eigenvalues and (ii) a global constraint determining the number of chiral crossings on rotation axes. Together with the fermion doubling theorem, these laws describe all conditions that a network of chiral band crossing must satisfy. We apply the fundamental laws to prove the existence of enforced double Weyl points, nodal planes, and generic Weyl points, among others. In addition, we show that chiral space group symmetries can not stabilize nodal lines with finite Chern numbers. Combining the local constraint with explicit low-energy models, we determine the generic topological phase diagrams of all multifold crossings. Remarkably, we find a fourfold crossing with Chern number 5, which exceeds the previously conceived maximum Chern number of 4. We identify materials crystallizing in space group 198, such as B20 materials and BaAsPt, as suitable compounds with this Chern number 5 crossing.},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{ghara_magnetization_2023,

title = {Magnetization reversal through an antiferromagnetic state},

author = {S. Ghara and E. Barts and K. V. Vasin and D. Kamenskyi and L. Prodan and V. Tsurkan and I. Kézsmárki and M. Mostovoy and J. Deisenhofer},

doi = {10.1038/s41467-023-40722-y},

year  = {2023},

date = {2023-08-01},

urldate = {2023-08-01},

journal = {Nat. Commun.},

volume = {14},

number = {1},

pages = {5174},

abstract = {Magnetization reversal in ferro- and ferrimagnets is a well-known archetype of non-equilibrium processes, where the volume fractions of the oppositely magnetized domains vary and perfectly compensate each other at the coercive magnetic field. Here, we report on a fundamentally new pathway for magnetization reversal that is mediated by an antiferromagnetic state. Consequently, an atomic-scale compensation of the magnetization is realized at the coercive field, instead of the mesoscopic or macroscopic domain cancellation in canonical reversal processes. We demonstrate this unusual magnetization reversal on the Zn-doped polar magnet Fe2Mo3O8. Hidden behind the conventional ferrimagnetic hysteresis loop, the surprising emergence of the antiferromagnetic phase at the coercive fields is disclosed by a sharp peak in the field-dependence of the electric polarization. In addition, at the magnetization reversal our THz spectroscopy studies reveal the reappearance of the magnon mode that is only present in the pristine antiferromagnetic state. According to our microscopic calculations, this unusual process is governed by the dominant intralayer coupling, strong easy-axis anisotropy and spin fluctuations, which result in a complex interplay between the ferrimagnetic and antiferromagnetic phases. Such antiferro-state-mediated reversal processes offer novel concepts for magnetization control, and may also emerge for other ferroic orders.},

keywords = {A1, C4},

pubstate = {published},

tppubtype = {article}

}

@article{huber_quantum_2023,

title = {Quantum oscillations of the quasiparticle lifetime in a metal},

author = {N. Huber and V. Leeb and A. Bauer and G. Benka and J. Knolle and C. Pfleiderer and M. A. Wilde},

doi = {10.1038/s41586-023-06330-y},

issn = {0028-0836},

year  = {2023},

date = {2023-08-01},

urldate = {2023-08-01},

journal = {Nature},

volume = {621},

pages = {276},

abstract = {Following nearly a century of research, it remains a puzzle that the low-lying excitations of metals are remarkably well explained by effective single-particle theories of non-interacting bands(1-4). The abundance of interactions in real materials raises the question of direct spectroscopic signatures of phenomena beyond effective single-particle, single-band behaviour. Here we report the identification of quantum oscillations (QOs) in the three-dimensional topological semimetal CoSi, which defy the standard description in two fundamental aspects. First, the oscillation frequency corresponds to the difference of semiclassical quasiparticle (QP) orbits of two bands, which are forbidden as half of the trajectory would oppose the Lorentz force. Second, the oscillations exist up to above 50 K, in strong contrast to all other oscillatory components, which vanish below a few kelvin. Our findings are in excellent agreement with generic model calculations of QOs of the QP lifetime (QPL). Because the only precondition for their existence is a nonlinear coupling of at least two electronic orbits, for example, owing to QP scattering on defects or collective excitations, such QOs of the QPL are generic for any metal featuring Landau quantization with several orbits. They are consistent with certain frequencies in topological semimetals(5-9), unconventional superconductors(10,11), rare-earth compounds(12-14) and Rashba systems(15), and permit to identify and gauge correlation phenomena, for example, in two-dimensional materials(16,17) and multiband metals(18).},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{prodan_large_2023,

title = {Large ordered moment with strong easy-plane anisotropy and vortex-domain pattern in the kagome ferromagnet Fe_{3}Sn},

author = {L. Prodan and D. M. Evans and S. M. Griffin and A. Oestlin and M. Altthaler and E. Lysne and I. G. Filippova and S. Shova and L. Chioncel and V. Tsurkan and I. Kézsmárki},

doi = {10.1063/5.0155295},

issn = {0003-6951},

year  = {2023},

date = {2023-07-01},

urldate = {2023-07-01},

journal = {Appl. Phys. Lett.},

volume = {123},

number = {2},

pages = {021901},

abstract = {We report the magnetic anisotropy of kagome bilayer ferromagnet Fe3Sn probed by the bulk magnetometry and magnetic force microscopy (MFM) on high-quality single crystals. The dependence of magnetization on the orientation of the external magnetic field reveals strong easyplane magnetocrystalline anisotropy and anisotropy of the saturation magnetization. The leading magnetocrystalline anisotropy constant shows a monotonous increase from K-1 approximate to -1.0 x 10(6) J/m(3) at 300K to -1.3 x 10(6) J/m(3) at 2K. Our ab initio electronic structure calculations yield the value of total magnetic moment of 7.1 mu(B)=f.u. and a magnetocrystalline anisotropy energy density of -0.57meV=f.u. (-1.62 x 10(6)J/m(3)) both being in reasonable agreement with the experimental values. The MFM imaging reveals micrometer-scale magnetic vortices with weakly pinned cores that vanish at the saturation field of similar to 3T applied perpendicular to the kagome plane. The observed vortex-domain structure is well reproduced by the micromagnetic simulations, using the experimentally determined value of the anisotropy and exchange stiffness. (c) 2023 Author(s).},

keywords = {A4, A5},

pubstate = {published},

tppubtype = {article}

}

@article{deyerling_electronic_2023,

title = {Electronic structure of CeAuAl_{3} using density functional theory},

author = {A. Deyerling and M. A. Wilde and C. Pfleiderer},

doi = {10.21468/SciPostPhysProc.11.008},

year  = {2023},

date = {2023-06-05},

urldate = {2023-06-05},

journal = {SciPost Phys. Proc.},

volume = {11},

pages = {008},

abstract = {We studied the magnetic properties and electronic structure of CeAuAl3 using density functional theory. This compound shows a large Sommerfeld coefficient, a Kondo temperature, TK=4K and antiferromagnetic order below TN=1.1K. We calculated the magnetic groundstate of CeAuAl3 and the magnetic anisotropy energies. Treating the 4f-electrons as localized with DFT+U we obtain a good match with the magnetic properties observed experimentally. We also report salient features of the electronic structure of CeAuAl3, including features of the Fermi surface and associated quantum oscillatory spectra, when the 4f-electrons are treated either as localized or itinerant.},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{kumar_low-temperature_2023,

title = {Low-temperature antiferromagnetic order in orthorhombic CePdAl_{3}},

author = {V. Kumar and A. Bauer and C. Franz and J. Spallek and R. Schönmann and M. Stekiel and A. Schneidewind and M. A. Wilde and C. Pfleiderer},

doi = {10.1103/PhysRevResearch.5.023157},

year  = {2023},

date = {2023-06-01},

urldate = {2023-06-01},

journal = {Phys. Rev. Research},

volume = {5},

number = {2},

pages = {023157},

abstract = {We report the magnetization, ac susceptibility, and specific heat of optically float-zoned single crystals of CePdAl3. In comparison to the properties of polycrystalline CePdAl3 reported in the literature, which displays a tetragonal crystal structure and no long-range magnetic order, our single crystals exhibit an orthorhombic structure (𝐶⁢𝑚⁢𝑐⁢𝑚) and antiferromagnetic order below a Néel temperature 𝑇1=5.6 K. The specific heat at zero field shows two anomalies, namely, a broad transition at 𝑇1=5.6 K followed by a 𝜆-anomaly at 𝑇2=5.4 K. A conservative estimate of the Sommerfeld coefficient of the electronic specific heat, 𝛾=121mJK−2mol−1, indicates a moderately enhanced heavy-fermion ground state. A twin microstructure evolves in the family of planes spanned by the basal plane lattice vectors 𝐚o and 𝐜o , with the magnetic hard axis 𝐛o common to all twins. The antiferromagnetic state is characterized by a strong ao, co easy-plane magnetic anisotropy where the ao direction is the easy axis in the easy plane. A spin-flop transition induced under magnetic field along the easy directions, results in complex magnetic phase diagrams. Taken together, our results reveal a high sensitivity of the magnetic and electronic properties of CePdAl3 to its structural modifications.},

keywords = {A6},

pubstate = {published},

tppubtype = {article}

}

@article{schilberth_nodal-line_2023,

title = {Nodal-line resonance generating the giant anomalous Hall effect of Co_{3}Sn_{2}S_{2}},

author = {F. Schilberth and M. -C. Jiang and S. Minami and M. A. Kassem and F. Mayr and T. Koretsune and Y. Tabata and T. Waki and H. Nakamura and G. -Y. Guo and R. Arita and I. Kézsmárki and S. Bordacs},

doi = {10.1103/PhysRevB.107.214441},

issn = {2469-9950},

year  = {2023},

date = {2023-06-01},

urldate = {2023-06-01},

journal = {Phys. Rev. B},

volume = {107},

number = {21},

pages = {214441},

abstract = {Giant anomalous Hall effect (AHE) and magneto-optical activity can emerge in magnets with topologically nontrivial degeneracies. However, identifying the specific band-structure features such as Weyl points, nodal lines, or planes which generate the anomalous response is a challenging issue. Since the low-energy interband transitions can govern the static AHE, we addressed this question in the prototypical magnetic Weyl semimetal Co3Sn2S2 also hosting nodal lines by broadband polarized reflectivity and magneto-optical Kerr effect spectroscopy with a focus on the far-infrared range. In the linear dichroism spectrum we observe a strong resonance at 40 meV, which also appears in the optical Hall conductivity and primarily determines the static AHE, and thus confirms its intrinsic origin. Our material-specific theory reproduces the experimental data remarkably well and shows that strongly tilted nodal-line segments around the Fermi energy generate the resonance. While the Weyl points only give vanishing contributions, these segments of the nodal lines gapped by the spin-orbit coupling dominate the low-energy optical response and generate the giant AHE.},

keywords = {A1},

pubstate = {published},

tppubtype = {article}

}

@article{toth_broadband_2023,

title = {Broadband magnetic resonance spectroscopy in MnSc_{2}S_{4}},

author = {B. Tóth and K. Amelin and T. Rõõm and U. Nagel and A. Bauernfeind and V. Tsurkan and L. Prodan and H. -A. Krug von Nidda and M. Scheffler and I. Kézsmárki and others},

doi = {10.1038/s41598-023-37911-6},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Sci. Rep.},

volume = {13},

number = {1},

pages = {11069},

abstract = {Recent neutron scattering experiments suggested that frustrated magnetic interactions give rise to antiferromagnetic spiral and fractional skyrmion lattice phases in MnSc2S4. Here, to trace the signatures of these modulated phases, we studied the spin excitations of MnSc2S4 by THz spectroscopy at 300 mK and in magnetic fields up to 12 T and by broadband microwave spectroscopy at various temperatures up to 50 GHz. We found a single magnetic resonance with frequency linearly increasing in field. The small deviation of the Mn2+ ion g-factor from 2},

keywords = {B4},

pubstate = {published},

tppubtype = {article}

}

@article{mohanty_disordered_2023,

title = {Disordered ground state in the spin-orbit coupled J_{eff} = 1/2 distorted honeycomb magnet BiYbGeO_{5}},

author = {S. Mohanty and S. S. Islam and N. Winterhalter-Stocker and A. Jesche and G. Simutis and Ch. Wang and Z. Guguchia and J. Sichelschmidt and M. Baenitz and A. A. Tsirlin and P. Gegenwart and R. Nath},

doi = {10.1103/PhysRevB.108.134408},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Phys. Rev. B},

volume = {108},

number = {13},

pages = {134408},

abstract = {We delineate quantum magnetism in the strongly spin-orbit coupled distorted honeycomb lattice antiferromagnet BiYbGeO5. Our magnetization and heat capacity measurements reveal that its low-temperature behavior is well described by an effective J(eff) = 1/2 Kramers doublet of Yb3+. The ground state is nonmagnetic with a tiny spin gap. Temperature-dependent magnetic susceptibility, magnetization isotherm, and heat capacity can be modeled well assuming isolated spin dimers with anisotropic exchange interactions J(Z) similar or equal to 2.6 K and J(XY) similar or equal to 1.3 K. Heat capacity measurements backed by muon spin relaxation suggest the absence of magnetic long-range order down to at least 80 mK both in zero field and in applied fields. This sets BiYbGeO5 apart from Yb2Si2O7, with its unusual regime of magnon Bose-Einstein condensation, and suggests negligible interdimer couplings, despite only a weak structural deformation of the honeycomb lattice.},

keywords = {B3},

pubstate = {published},

tppubtype = {article}

}

@article{bader_geometrical_2023,

title = {Geometrical frustration and incommensurate magnetic order in Na_{3}RuO_{4} with two triangular motifs},

author = {V. P. Bader and C. Ritter and E. Papke and P. Gegenwart and A. A. Tsirlin},

doi = {10.1103/PhysRevB.108.144424},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Phys. Rev. B},

volume = {108},

number = {14},

pages = {144424},

keywords = {B3},

pubstate = {published},

tppubtype = {article}

}

@article{kadow_single-hole_2023,

title = {Single-hole spectra of Kitaev spin liquids: From dynamical Nagaoka ferromagnetism to spin-hole fractionalization},

author = {W. Kadow and H. -K. Jin and J. Knolle and M. Knap},

doi = {10.1038/s41535-024-00641-7},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {npj Quantum Mater.},

volume = {9},

pages = {32},

keywords = {C6},

pubstate = {published},

tppubtype = {article}

}

@article{muller_temperature_2023,

title = {Temperature dependence of the magnon-phonon interaction in high overtone bulk acoustic resonator-ferromagnetic thin film hybrids},

author = {M. Müller and J. Weber and S. T. B. Goennenwein and S. V. Kusminskiy and R. Gross and M. Althammer and H. Huebl},

doi = {10.1103/PhysRevApplied.21.034032},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Phy. Rev. Applied},

volume = {21},

number = {3},

pages = {034032},

keywords = {C3},

pubstate = {published},

tppubtype = {article}

}

@article{kawano_unconventional_2023,

title = {Unconventional spin transport in strongly correlated kagome systems},

author = {M. Kawano and F. Pollmann and M. Knap},

doi = {10.1103/PhysRevB.109.L121111},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {12},

pages = {L121111},

keywords = {C5},

pubstate = {published},

tppubtype = {article}

}