@article{hollricherCyclotronMassselectiveHaas2026,

title = {Cyclotron mass-selective de Haas–van Alphen measurements using temperature modulation},

author = {M. Hollricher and A. Bauer and L. Maximov and L. Feenstra and C. Pfleiderer and M. A. Wilde},

url = {https://doi.org/10.1063/5.0334928},

doi = {10.1063/5.0334928},

issn = {0003-6951},

year  = {2026},

date = {2026-07-27},

urldate = {2026-07-27},

journal = {Appl. Phys. Lett.},

volume = {129},

number = {4},

pages = {041902},

abstract = {We present a temperature-modulated de Haas–van Alphen measurement technique that allows selective addressing of quantum oscillations with different effective masses m∗ using a non-monotonic amplitude evolution with temperature and magnetic field, governed by the temperature derivative of the Lifshitz–Kosevich factor. The technique relies on harmonic modulation of the sample temperature and phase-sensitive detection of quantum oscillations in the voltage induced in a pickup coil. We use a set of frequencies with strong Zeeman-driven harmonic content in the compensated topological semimetal MoSi2 as a natural linear mass comb ranging from 1 m∗ to 13 m∗ to demonstrate the tunability of the mass-dependent quantum oscillation amplitudes experimentally. The technique allows us to reliably isolate weak contributions of heavy orbits that are inaccessible in conventional de Haas–van Alphen frequency spectra because their frequency peaks overlap with much stronger frequency peaks of lighter orbits.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{gagglBulkSuperconductivityKagome2026,

title = {Bulk superconductivity in the kagome metal YRu_{3}B_{2}},

author = {T. Gaggl and R. Misawa and M. Kriener and Y. Tanaka and R. Yamada and M. Hirschberger},

url = {https://doi.org/10.1088/1402-4896/ae3c65},

doi = {10.1088/1402-4896/ae3c65},

year  = {2026},

date = {2026-02-05},

urldate = {2026-02-01},

journal = {Phys. Scr.},

volume = {101},

number = {5},

pages = {055912},

abstract = {Materials with a kagome lattice have been heavily studied for their exotic electronic band structure, geometrical frustration, high-temperature charge-order transitions, and unconventional electron-phonon coupling. In LaRu3Si2, it was proposed that electronic flat bands conspire with the characteristic phonon spectrum of the kagome lattice to drive enhanced superconductivity at Tc = 6.8 K. Here, we report bulk superconductivity in the structural analogue YRu3B2, which hosts a pristine kagome lattice. We observe a superconducting transition at Tc = 0.7 K through magnetization, resistivity, and heat-capacity measurements in this novel kagome metal.},

note = {datadoi: (10.5281/zenodo.18276372)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weberNonreciprocalZoneBoundary2026,

title = {Nonreciprocal zone boundary magnon propagation in Cu_{2}OSeO_{3}},

author = {T. Weber and N. Heinsdorf and M. Stekiel and P. Steffens and A. P. Schnyder and C. Pfleiderer},

url = {https://link.aps.org/doi/10.1103/q77j-5g59},

doi = {10.1103/q77j-5g59},

year  = {2026},

date = {2026-01-29},

urldate = {2026-01-29},

journal = {Phys. Rev. B},

volume = {113},

number = {2},

pages = {L020414},

publisher = {American Physical Society},

abstract = {Inelastic neutron scattering in the chiral magnet Cu2⁢OSeO3 reveals strong nonreciprocal effects on magnon propagation at the boundary of the nuclear Brillouin zone. The nonreciprocal response is strongest at a central position between the zone corner and the edge midpoint. We explain these results using an effective linear spin-wave model. While directional effects in chiral magnets have so far only been known to exist at low momenta close to the center of the Brillouin zone, the present study shows that nonreciprocity persists at the highest possible reduced momenta. The observed magnons show very little damping within the limits of our experimental resolution, making them of great interest for the fundamental research on compact, high-frequency magnonic applications.},

note = {datadoi: 10.5281/zenodo.16600991},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{misawaSuccessiveOrthorhombicDistortions2025,

title = {Successive orthorhombic distortions in kagome metals by molecular orbital formation},

author = {R. Misawa and S. Kitou and R. Yamada and T. Gaggl and R. Nakano and Y. Shibata and Y. Okamura and M. Kriener and P. R. Baral and Y. Nakamura and Y. Ōnuki and Y. Takahashi and T. Arima and M. Jovanovic and L. M. Schoop and M. Hirschberger},

url = {https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/adma.202513015},

doi = {10.1002/adma.202513015},

year  = {2025},

date = {2025-12-05},

urldate = {2025-12-01},

journal = {Adv. Mater.},

pages = {e13015},

abstract = {Abstract The kagome lattice, with its inherent frustration, hosts a plethora of exotic phenomena, including the emergence of 3q charge-density-wave order. The high rotational symmetry required to realize such an unconventional charge order is broken in many kagome materials by orthorhombic distortions at high temperature, the origin of which remains much less examined despite their ubiquity. In this study, synchrotron X-ray diffraction reveals a structural phase transition from a parent hexagonal structure to an orthorhombic groundstate, mediated by a critical regime with diffuse scattering in the prototypical kagome metals RRu3Si2 (R = Nd, Pr). Structural analysis uncovers partially ordered bonds between kagome layers in the orthorhombic phases. Accordingly, a short-range correlated dimer model on the kagome layers reproduces the diffuse scattering, with the short-range order arising from competing structures induced by the geometrical frustration of the kagome lattice. The observations point to molecular orbital formation between Ru $4d_zˆ2$ orbitals as the driving force behind the transition, consistent with ab initio calculations. A framework based on electronegativity and a tolerance factor is proposed to evaluate the stability of the hexagonal phase in various kagome metals, guiding the design of highly symmetric materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{huberFermiSurfaceMagnetic2025,

title = {Fermi surface and magnetic breakdown in PdGa},

author = {N. Huber and I. Volkau and A. Engelhardt and I. Sheikin and A. Bauer and C. Pfleiderer and M. A. Wilde},

url = {https://link.aps.org/doi/10.1103/kwgt-cryz},

doi = {10.1103/kwgt-cryz},

year  = {2025},

date = {2025-08-08},

urldate = {2025-08-08},

journal = {Phys. Rev. B},

volume = {112},

number = {8},

pages = {085116},

abstract = {We study the electronic structure of the chiral semimetal PdGa by means of the de Haas–van Alphen and Shubnikov–de Haas effect. We find that the Fermi surface of PdGa comprises multiple pockets split by spin-orbit coupling. We compare our experimental findings with the band structure calculated ab initio. We demonstrate that the quantum oscillation spectra can be fully understood by considering topological nodal plane degeneracies at the Brillouin zone boundary and magnetic breakdown between individual Fermi-surface pockets. Expanding traditional analysis methods, we explicitly calculate magnetic breakdown frequencies and cyclotron masses while taking into account that extremal breakdown trajectories may reside away from the planes of the single-band orbits. We further analyze high-frequency contributions arising from breakdown trajectories involving multiple revolutions around the Fermi surface which are distinct from conventional harmonic frequencies. Our results highlight the existence of gaps induced by spin-orbit coupling throughout the band structure of PdGa, the relevance of nodal planes on the Brillouin zone boundary, and the necessity for a comprehensive analysis of magnetic breakdown.},

note = {datadoi: 10.5281/zenodo.15770032},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{leeb_field_2025,

title = {A Field Guide to Non-Onsager Quantum Oscillations in Metals},

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

url = {https://doi.org/10.1002/apxr.202400134},

doi = {10.1002/apxr.202400134},

year  = {2025},

date = {2025-02-25},

urldate = {2025-02-25},

journal = {Adv. Phys. Res.},

volume = {4},

number = {4},

pages = {2400134},

abstract = {Abstract Quantum oscillation (QO) measurements constitute a powerful method to measure the Fermi surface (FS) properties of metals. The observation of QOs is usually taken as strong evidence for the existence of extremal cross-sectional areas of the FS according to the famous Onsager relation. Here, mechanisms that generate QO frequencies that defy the Onsager relation are reviewed and material candidates are discussed. These include magnetic breakdown, magnetic interaction, chemical potential oscillations, and Stark quantum interference, most of which lead to signals occurring at combinations of ?parent? Onsager frequencies. A special emphasis is put on the recently discovered mechanism of quasi-particle lifetime oscillations (QPLOs). This work aims to provide a field guide that allows, on the one hand, to distinguish such non-Onsager QOs from conventional QOs arising from extremal cross sections and, on the other hand, to distinguish the various non-Onsager mechanisms from each other. A practical classification of non-Onsager QOs is given in terms of the prerequisites for their occurrence and their characteristics. It is shown that, in particular, the recently discovered QPLOs may pose significant challenges for the interpretation of QO spectra, as they may occur quite generically as frequency differences in multi-orbit systems, without the necessity of visible ?parent? frequencies in the spectrum, owing to a strongly suppressed temperature dephasing of QPLOs. An extensive list of material candidates is presented where QPLOs may represent an alternative explanation for the observation of unexpected QO frequencies.},

keywords = {},

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 = {},

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 = {},

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 = {2024-05-06},

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 = {},

pubstate = {published},

tppubtype = {article}

}

@article{simethTopologicalAspectsMultik2024,

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 = {2024-02-29},

urldate = {2024-02-29},

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

volume = {36},

number = {21},

pages = {215602},

abstract = {We advertise rare-earth intermetallics with high-symmetry crystal structures and competing interactions as a possible materials platform hosting spin structures with non-trivial topological properties. Focusing on the series of cubic RCu compounds, where R = Ho, Er, Tm, the bulk properties of these systems display exceptionally rich magnetic phase diagrams hosting an abundance of different phase pockets characteristic of antiferromagnetic order in the presence of delicately balanced interactions. The electrical transport properties exhibit large anomalous contributions suggestive of topologically non-trivial winding in the electronic and magnetic structures. Neutron diffraction identifies spontaneous long-range magnetic order in terms of commensurate and incommensurate variations of 

 antiferromagnetism with the possibility for various multi-k configurations. Motivated by general trends in these materials, we discuss the possible existence of topologically non-trivial winding in real and reciprocal space in the class of RCu compounds including antiferromagnetic skyrmion lattices. Putatively bringing together different limits of non-trivial topological winding in the same material, the combination of properties in RCu systems promises access to advanced functionalities.},

note = {datadoi: (10.5281/zenodo.10047782)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{huberQuantumOscillationsQuasiparticle2023,

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},

url = {https://doi.org/10.1038/s41586-023-06330-y},

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

issn = {0028-0836},

year  = {2023},

date = {2023-08-02},

urldate = {2023-08-02},

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).},

note = {datadoi: 10.5281/zenodo.7957066},

keywords = {},

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 = {},

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 = {},

pubstate = {published},

tppubtype = {article}

}