Kagome Lattice Promotes Chiral Spin Fluctuations.

Dynamical spin fluctuations in magnets can be endowed with a slight bent toward left- or right-handed chirality by Dzyaloshinskii-Moriya interactions. However, little is known about the crucial role of lattice geometry on these chiral spin fluctuations and on fluctuation-related transport anomalies driven by the quantum-mechanical (Berry) phase of conduction electrons. Via thermoelectric Nernst effect and electric Hall effect experiments, we detect chiral spin fluctuations in the paramagnetic regime of a kagome lattice magnet; these signals are largely absent in a comparable triangular lattice magnet. Supported by Monte Carlo calculations, we identify lattices with at least two dissimilar plaquettes as most promising for Berry phase phenomena driven by thermal fluctuations in paramagnets.

[1]  Y. Tokura,et al.  Entropy-Assisted, Long-Period Stacking of Honeycomb Layers in an AlB2-Type Silicide. , 2022, Journal of the American Chemical Society.

[2]  Y. Tokura,et al.  Large Hall and Nernst responses from thermally induced spin chirality in a spin-trimer ferromagnet , 2021, Proceedings of the National Academy of Sciences.

[3]  Luyi Yang,et al.  Resonant optical topological Hall conductivity from skyrmions , 2021, 2106.02641.

[4]  Y. Tokura,et al.  Nano-to-micro spatiotemporal imaging of magnetic skyrmion’s life cycle , 2021, Science Advances.

[5]  I. Mertig,et al.  Colossal topological Hall effect at the transition between isolated and lattice-phase interfacial skyrmions , 2021, Nature Communications.

[6]  Luyi Yang,et al.  Anomalous Kerr effect in SrRuO3 thin films , 2020 .

[7]  S. Eisebitt,et al.  Observation of fluctuation-mediated picosecond nucleation of a topological phase , 2020, Nature Materials.

[8]  Y. Tokura,et al.  Nanometric square skyrmion lattice in a centrosymmetric tetragonal magnet , 2020, Nature Nanotechnology.

[9]  Kamran Behnia,et al.  Anomalous transverse response of Co2MnGa and universality of the room-temperature αijA/σijA ratio across topological magnets , 2020, 2001.10264.

[10]  Y. Tokura,et al.  Topological Nernst Effect of the Two-Dimensional Skyrmion Lattice. , 2019, Physical review letters.

[11]  Binghai Yan,et al.  Intrinsic Anomalous Nernst Effect Amplified by Disorder in a Half-Metallic Semimetal , 2019, Physical Review X.

[12]  Y. Mokrousov,et al.  Topological–chiral magnetic interactions driven by emergent orbital magnetism , 2019, Nature Communications.

[13]  Y. Kato,et al.  Colossal Enhancement of Spin-Chirality-Related Hall Effect by Thermal Fluctuation , 2018, Physical Review Applied.

[14]  Su-Yang Xu,et al.  High-frequency rectification via chiral Bloch electrons , 2018, Science Advances.

[15]  Jia-ling Wang,et al.  Spin chirality fluctuation in two-dimensional ferromagnets with perpendicular magnetic anisotropy , 2018, Nature Materials.

[16]  Binghai Yan,et al.  Finite-temperature violation of the anomalous transverse Wiedemann-Franz law , 2018, Science Advances.

[17]  Y. Tokura,et al.  Skyrmion phase and competing magnetic orders on a breathing kagomé lattice , 2018, Nature Communications.

[18]  K. Katoh,et al.  Spin trimer formation in the metallic compound Gd3Ru4Al12 with a distorted kagome lattice structure , 2018, Physical Review B.

[19]  Y. Tokura,et al.  Skyrmion lattice with a giant topological Hall effect in a frustrated triangular-lattice magnet , 2018, Science.

[20]  N. Nagaosa,et al.  Spin chirality induced skew scattering and anomalous Hall effect in chiral magnets , 2018, Science Advances.

[21]  J. Sinova,et al.  B–T phase diagram of Pd/Fe/Ir(111) computed with parallel tempering Monte Carlo , 2017, New Journal of Physics.

[22]  J. Zang,et al.  Thermally Driven Topology in Chiral Magnets , 2017, 1705.07353.

[23]  K. Iyer,et al.  Magnetic behavior of Gd3Ru4Al12, a layered compound with distorted kagomé net , 2016, Journal of physics. Condensed matter : an Institute of Physics journal.

[24]  E. Simon,et al.  Complex magnetic phase diagram and skyrmion lifetime in an ultrathin film from atomistic simulations , 2015, 1510.04812.

[25]  D. Nocera,et al.  Topological Magnon Bands in a Kagome Lattice Ferromagnet. , 2015, Physical review letters.

[26]  C. Pfleiderer,et al.  Giant generic topological Hall resistivity of MnSi under pressure , 2013, 1404.3734.

[27]  Daniel G. Nocera,et al.  Fractionalized excitations in the spin-liquid state of a kagome-lattice antiferromagnet , 2012, Nature.

[28]  S. Gemming,et al.  Crystallographic superstructure in R2PdSi3 compounds (R = heavy rare earth) , 2011 .

[29]  A. Yamamoto,et al.  Z2-Vortex Ordering of the Triangular-Lattice Heisenberg Antiferromagnet , 2009, 0909.0121.

[30]  Patrick A. Lee,et al.  Theory of the thermal Hall effect in quantum magnets. , 2009, Physical review letters.

[31]  P M Bentley,et al.  Chiral paramagnetic skyrmion-like phase in MnSi. , 2009, Physical review letters.

[32]  P. Böni,et al.  Topological Hall effect in the A phase of MnSi. , 2009, Physical review letters.

[33]  A. Vishwanath,et al.  Chirality induced anomalous-Hall effect in helical spin crystals , 2007, 0706.1841.

[34]  A. Vishwanath,et al.  Theory of helical spin crystals: Phases, textures, and properties , 2006, cond-mat/0608128.

[35]  Naoto Nagaosa,et al.  Intrinsic versus extrinsic anomalous Hall effect in ferromagnets. , 2006, Physical review letters.

[36]  A. Vishwanath,et al.  Theory of the helical spin crystal: a candidate for the partially ordered state of MnSi. , 2006, Physical review letters.

[37]  P. Bruno,et al.  Topological Hall effect and Berry phase in magnetic nanostructures. , 2003, Physical review letters.

[38]  M. Salamon,et al.  Skyrmion strings and the anomalous Hall effect in CrO2. , 2002, Physical review letters.

[39]  M. Salamon,et al.  Charge transport in manganites: Hopping conduction, the anomalous Hall effect, and universal scaling , 2000, cond-mat/0012462.

[40]  S. Murakami,et al.  Spin Anisotropy and Quantum Hall Effect in the Kagomé Lattice : Chiral Spin State based on a Ferromagnet , 1999, cond-mat/9912206.

[41]  M. Salamon,et al.  Magnetotransport in manganites and the role of quantal phases: theory and experiment. , 1999, Physical review letters.

[42]  R. Gladyshevskii,et al.  Structure of Gd3Ru4Al12, a new member of the EuMg5.2 structure family with minority-atom clusters , 1993 .

[43]  J. Yakinthos,et al.  Magnetic properties of the ternary rare earth silicides R2PdSi3 (R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm and Y) , 1990 .

[44]  Lau,et al.  Numerical investigation of the role of topological defects in the three-dimensional Heisenberg transition. , 1989, Physical review. B, Condensed matter.

[45]  C. Dasgupta,et al.  Role of topological defects in the phase transition of the three-dimensional Heisenberg model , 1988 .

[46]  M. Berry.  Quantal phase factors accompanying adiabatic changes , 1984, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[47]  S. Miyashita,et al.  Phase Transition of the Two-Dimensional Heisenberg Antiferromagnet on the Triangular Lattice , 1984 .

[48]  Robert Jan. Williams,et al.  The Geometrical Foundation of Natural Structure: A Source Book of Design , 1979 .

[49]  C. Slaughter.  Shapes , 2020 .

[50]  A. N. Bogdanov,et al.  Thermodynamically stable "vortices" in magnetically ordered crystals. The mixed state of magnets , 1989 .

[51]  Alan Holden,et al.  Shapes, space, and symmetry , 1971 .