Monoaxial Dzyaloshinskii-Moriya interaction-induced topological Hall effect in a new chiral-lattice magnet GdPt2_2B

We investigate the topological Hall effect (THE) in the monoaxial chiral crystal GdPt$_2$B, a recently discovered compound that exhibits putative helimagnetism below 87 K. The distinct THE was observed in GdPt2B in the magnetically ordered state. The scaling relations for anomalous and topological Hall conductivities differed from those of conventional models based on the scattering process. We further demonstrate the clear scaling behavior of the THE in a wide temperature range, which we attribute to the monoaxial Dzyaloshinskii-Moriya (DM) interaction under external magnetic fields perpendicular to the screw axis. The THE induced by the monoaxial DM interaction as well as the THE in a monoaxial chiral crystal of f-electron system are demonstrated in this study.Comment: 6 pages, 4 figures. To be published in Phys. Rev.

Large transverse thermoelectric effect induced by the mixed-dimensionality of Fermi surfaces

Abstract Transverse thermoelectric effect, the conversion of longitudinal heat current into transverse electric current, or vice versa, offers a promising energy harvesting technology. Materials with axis-dependent conduction polarity, known as p × n-type conductors or goniopolar materials, are potential candidate, because the non-zero transverse elements of thermopower tensor appear under rotational operation, though the availability is highly limited. Here, we report that a ternary metal LaPt2B with unique crystal structure exhibits axis-dependent thermopower polarity, which is driven by mixed-dimensional Fermi surfaces consisting of quasi-one-dimensional hole sheet with out-of-plane velocity and quasi-two-dimensional electron sheets with in-plane velocity. The ideal mixed-dimensional conductor LaPt2B exhibits an extremely large transverse Peltier conductivity up to ∣α y x ∣ = 130 A K−1 m−1, and its transverse thermoelectric performance surpasses those of topological magnets utilizing the anomalous Nernst effect. These results thus manifest the mixed-dimensionality as a key property for efficient transverse thermoelectric conversion