@article{ishiharaCollinearFerromagnetismReduced2026-06-222026,

title = {Collinear ferromagnetism with reduced moment length in kagome magnet Nd_{3⁢}Ru_{4}⁢Al_{12}},

author = {Y. Ishihara and Ryota Nakano and R. Yamada and T. Nomoto and P. R. Baral and M. M. Hirschmann and K. Gautam and K. K. Kolincio and A. Kikkawa and S. Aji and H. Saitoh and M. Matsuda and Y. Taguchi and T. Arima and Y. Tokura and T. Nakajima and M. Hirschberger},

url = {http://dx.doi.org/10.1103/9pvl-33xc},

doi = {10.1103/9pvl-33xc},

issn = {2469-9969},

year  = {2026},

date = {2026-06-02},

urldate = {2026-06-01},

journal = {Phys. Rev. B},

volume = {113},

number = {21},

publisher = {American Physical Society (APS)},

abstract = {We determine the magnetic ground state of the kagome lattice magnet Nd3⁢Ru4⁢Al12 by single-crystal neutron diffraction, supported by experiments with polarized neutrons. We identify this material as a collinear ferromagnet (“hex-FM”) with uniform moment length and ordering vector Q=0, in contrast to a previous, seminal report that proposed unequal moment lengths on two Nd sites, here called the “ortho-FM” state. Our analysis of the flipping ratio in polarized neutron scattering is consistent with the hex-FM state. The results provide a microscopic basis for understanding the large fluctuation-induced Hall and Nernst responses near TC≈41K, as previously reported for Nd3⁢Ru4⁢Al12.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yunStripeAntiferromagnetismVan2026,

title = {Stripe antiferromagnetism in the van der Waals metal HoTe_{3} decoupled from charge density wave order},

author = {W. Yun and R. Nakano and R. Misawa and R. Yamada and S. Akatsuka and Y. Ōnuki and P. R. Baral and S. Esser and H. Saitoh and R. Kiyanagi and T. Ohhara and T. Nakajima and T. Arima and M. Hirschberger},

url = {https://link.aps.org/doi/10.1103/q39f-b32w},

doi = {10.1103/q39f-b32w},

year  = {2026},

date = {2026-04-21},

urldate = {2026-04-01},

journal = {Phys. Rev. B},

publisher = {American Physical Society},

abstract = {The RTe3 (R = rare earth) family of layered van der Waals (vdW) compounds hosts coexisting magnetic and charge density wave (CDW) orders, yet the interplay between these degrees of freedom remains largely unexplored. Combining polarized and unpolarized neutron diffraction on single crystals of HoTe3, we identify two distinct antiferromagnetic (AFM) phases, both exhibiting a collinear ↑↑↓↓ motif within individual vdW layers. The two phases are distinguished by the vdW stacking of magnetic layers: ferromagnetic (FM) stacking in the higher-temperature AFM-II phase, here termed “vertical-stripe”, and AFM stacking in the AFM-I ground state, here termed “tilted-stripe”; the two phases have propagation vectors qm2 = (0.48, 0, 0) and qm1 = (0.5, 0.5, 0), respectively. In contrast to the CDW-driven exotic magnetism in DyTe3, TbTe3, and GdTe3, we find no evidence for coupling between magnetism and CDW in HoTe3. The presence of a checkerboard-type charge order in HoTe3 may be detrimental for realizing coupled spin/charge order parameters in layered vdW systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nakanoPerfectlyHarmonicSpin2026,

title = {Perfectly harmonic spin cycloid and multi-Q textures in the Weyl semimetal GdAlSi},

author = {R. Nakano and R. Yamada and J. Bouaziz and M. Colling and M. Gen and K. Shoriki and Y. Okamura and A. Kikkawa and R. Misawa and P. R. Baral and S. Kitou and Y. Nakamura and H. Ohsumi and Y. Tanaka and H. Sagayama and H. Nakao and Y. Ishihara and K. Gautam and O. Fabelo and Y. Taguchi and Y. Takahashi and M. Tokunaga and T. Arima and Y. Tokura and R. Arita and J. Masell and S. Hayami and M. Hirschberger},

url = {http://dx.doi.org/10.1038/s41467-026-69452-7},

doi = {10.1038/s41467-026-69452-7},

issn = {2041-1723},

year  = {2026},

date = {2026-02-23},

urldate = {2026-02-01},

journal = {Nat. Commun.},

volume = {17},

number = {1},

publisher = {Springer Science and Business Media LLC},

abstract = {A fundamental question in condensed matter physics concerns how topological electronic states are influenced by many-body correlations, and magnetic Weyl semimetals represent an important material platform to address this problem. However, the magnetic structures realized in these materials are limited, and in particular, no clear example of an undistorted helimagnetic state has been definitively identified. Here, we report clear evidence of a harmonic helimagnetic cycloid with an incommensurate magnetic propagation vector Q in the Weyl semimetal GdAlSi via resonant elastic X-ray scattering, including rigorous polarization analysis. This cycloidal structure is consistent with the Dzyaloshinskii–Moriya interaction prescribed by the polar crystal structure of GdAlSi. Upon applying a magnetic field, the cycloid undergoes a transition to a novel multi-Q state. This field-induced, noncoplanar texture is consistent with our numerical spin model, which incorporates the Dzyaloshinskii–Moriya interaction and, crucially, anisotropic exchange interactions. The perfectly harmonic Weyl helimagnet GdAlSi serves as a prototypical platform to study electronic correlation effects in periodically modulated Weyl semimetals.},

note = {datadoi: 10.5281/zenodo.18228967},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yamaguchiTopologicalThermalHall2026,

title = {Topological thermal Hall effect and nondissipative transport of the nanometric skyrmion lattice in Gd_{2}PdSi_{3}},

author = {D. Yamaguchi and P. Mokhtari and R. Yamada and A. Kikkawa and Y. Taguchi and Y. Tokura and M. Hirschberger},

url = {http://dx.doi.org/10.1093/pnasnexus/pgag041},

doi = {10.1093/pnasnexus/pgag041},

issn = {2752-6542},

year  = {2026},

date = {2026-02-23},

urldate = {2026-02-01},

journal = {PNAS Nexus},

volume = {5},

number = {3},

publisher = {Oxford University Press (OUP)},

abstract = {We report the first observation of a topological thermal Hall effect (tTHE) of electrons moving through a magnetic skyrmion lattice (SkL) of short period, where the skyrmion diameter is only a few nanometers. In the hexagonal intermetallic Gd2PdSi3, we observe a characteristic anomaly in the magnetic field dependence of the thermal Hall conductivity κxy, which scales well with the anomaly in the electrical Hall conductivity σxy and is closely related to the topological winding number of the SkL ground state. The relative magnitude of entropy and charge currents, defined as the Lorenz ratio ∼κxy/(σxyT), is consistent with a nondissipative, or intrinsic, mechanism for the topological Hall effect. We stress that the Berry phase in momentum space (k-space) causes such a nondissipative Hall transport, independent of the carrier relaxation time.},

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{yamadaEmergentElectricField2026,

title = {Emergent electric field induced by dissipative sliding dynamics of domain walls in a Weyl magnet},

author = {R. Yamada and D. Kurebayashi and Y. Fujishiro and S. Okumura and D. Nakamura and F. S. Yasin and T. Nakajima and T. Yokouchi and A. Kikkawa and Y. Taguchi and Y. Tokura and O. A. Tretiakov and M. Hirschberger},

url = {https://doi.org/10.1038/s41567-025-03124-z},

doi = {10.1038/s41567-025-03124-z},

year  = {2026},

date = {2026-01-15},

urldate = {2026-01-01},

journal = {Nat. Phys.},

volume = {22},

number = {2},

pages = {239–244},

abstract = {The dynamic motion of topological defects in magnets induces an emergent electric field, as exemplified by the continuous flow of skyrmion vortices. However, the electrodynamics underlying this emergent field remains poorly understood. In this context, magnetic domain walls—one-dimensional topological defects with two collective modes, sliding and spin-tilt—offer a promising platform for exploration. Here we demonstrate that the dissipative motion of domain walls under oscillatory current excitation generates an emergent electric field. We image domain patterns and quantify the domain-wall length under applied magnetic fields in mesoscopic devices based on the magnetic Weyl semimetal NdAlSi. These devices exhibit exceptionally strong domain-wall scattering and a pronounced emergent electric field, as observed in the imaginary component of the complex impedance. Spin dynamics simulations reveal that domain-wall sliding dominates over spin-tilting, in which the phase delay of the domain-wall motion with respect to the driving force impacts the emergent electric field. Our findings establish domain-wall dynamics as a platform for studying emergent electromagnetic fields and motivate further investigations of the coupled motion of magnetic solitons and conduction electrons.},

note = {datadoi: (10.5281/zenodo.17188494)},

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{yamadaMetallicPwaveMagnet2025,

title = {A metallic p-wave magnet with commensurate spin helix},

author = {R. Yamada and M. T. Birch and P. R. Baral and S. Okumura and R. Nakano and S. Gao and M. Ezawa and T. Nomoto and J. Masell and Y. Ishihara and K. K. Kolincio and I. Belopolski and H. Sagayama and H. Nakao and K. Ohishi and T. Ohhara and R. Kiyanagi and T. Nakajima and Y. Tokura and T. Arima and Y. Motome and M. M. Hirschmann and M. Hirschberger},

url = {https://doi.org/10.1038/s41586-025-09633-4},

doi = {10.1038/s41586-025-09633-4},

year  = {2025},

date = {2025-10-22},

urldate = {2025-10-01},

journal = {Nature},

volume = {646},

number = {8086},

pages = {837},

abstract = {Antiferromagnetic states with a spin-split electronic structure give rise to spintronic, magnonic and electronic phenomena despite (near-)zero net magnetization [1–7]. The simplest odd-parity spin splitting—p wave—was originally proposed to emerge from a collective instability in interacting electron systems [8–12]. Recent theory has identified a distinct route to realize p-wave spin-split electronic bands without strong correlations [13,14], termed p-wave magnetism. Here we demonstrate an experimental realization of a metallic p-wave magnet. The odd-parity spin splitting of delocalized conduction electrons arises from their coupling to an antiferromagnetic texture of localized magnetic moments: a coplanar spin helix whose magnetic period is an even multiple of the chemical unit cell, as revealed by X-ray scattering experiments. This texture breaks space-inversion symmetry but approximately preserves time-reversal symmetry up to a half-unit-cell translation—thereby fulfilling the symmetry conditions for p-wave magnetism. Consistent with theoretical predictions, our p-wave magnet shows a characteristic anisotropy in the electronic conductivity [13–15]. Relativistic spin–orbit coupling and a tiny spontaneous net magnetization further break time-reversal symmetry, resulting in a giant anomalous Hall effect (Hall conductivity >600 S cm−1, Hall angle >3%), for an antiferromagnet. Our model calculations show that the spin-nodal planes found in the electronic structure of p-wave magnets are readily gapped by a small perturbation to induce the anomalous Hall effect. We establish metallic p-wave magnets as an ideal platform to explore the functionality of spin-split electronic states in magnets, superconductors, and in spintronic devices.},

note = {datadoi: (10.5281/zenodo.17035625)},

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 = {},

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 = {},

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 = {},

pubstate = {published},

tppubtype = {article}

}