@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. Viola Kusminskiy and S. Geprägs and R. Gross and M. Althammer and H. Huebl},

doi = {10.1103/PhysRevB.109.024430},

year  = {2024},

date = {2024-01-01},

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{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{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 = {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 = {2024-01-01},

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{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{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{hu_phonon_2024,

title = {Phonon promoted charge density wave in topological kagome metal ScV_6Sn_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 = {},

pubstate = {published},

tppubtype = {article}

}

@article{wang_spin-orbit_2024,

title = {Spin-Orbit Excitons in a Correlated Metal: Raman Scattering Study of Sr_2RhO_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{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 = {},

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{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 = {2024-01-01},

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 = {},

pubstate = {published},

tppubtype = {article}

}

@article{toth_broadband_2023,

title = {Broadband magnetic resonance spectroscopy in MnSc_2S_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},

note = {Publisher: Nature Publishing Group UK London},

keywords = {},

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  = {2023},

date = {2023-12-01},

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{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 others},

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.},

note = {Publisher: APS},

keywords = {B3},

pubstate = {published},

tppubtype = {article}

}

@article{choi_finite_2023,

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  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Phys. Rev. B},

volume = {109},

number = {11},

pages = {115132},

note = {arXiv:2310.20566},

keywords = {C5},

pubstate = {published},

tppubtype = {article}

}

@article{panther_frustration_2023,

title = {Frustration relief and reorientation transition in the kagomelike dolerophanite Cu_2OSO_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{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 = {},

pubstate = {published},

tppubtype = {article}

}

@article{bader_geometrical_2023,

title = {Geometrical frustration and incommensurate magnetic order in Na_3RuO_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{prodan_large_2023,

title = {Large ordered moment with strong easy-plane anisotropy and vortex-domain pattern in the kagome ferromagnet Fe_3Sn},

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 = {},

pubstate = {published},

tppubtype = {article}

}

@article{ghara_magnetization_2023,

title = {Magnetization reversal through an antiferromagnetic state},

author = {S. Ghara and E. Barts and K. 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{breitner_metallic_2023,

title = {Metallic conductivity in Na-deficient structural domain walls in the spin-orbit Mott insulator Na_2IrO_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{schilberth_nodal-line_2023,

title = {Nodal-line resonance generating the giant anomalous Hall effect of Co_3Sn_2S_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{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 Marc 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 = {},

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},

note = {arXiv:2309.15157},

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},

note = {arXiv:2307.13725},

keywords = {C5},

pubstate = {published},

tppubtype = {article}

}