Transport in magnetic multidomain states of nodal semimetals

日時　2025年5月26日　（月）　16:00 – 17:00
場所　WPI-SKCM2研究棟（VBL）　2階　セミナー室（VBL204）
講師　鈴木 健士
(東邦大学理学部)

Coupling between conducting electrons and localized magnetic moments gives rise to various types of exotic charge transport phenomena including unconventional magnetoresistance beyond the Lorentz force effect, anomalous, and topological Hall effect. Nodal semimetals have been attracting much interest as promising arena for investigating such phenomena because their electronic band structure with a small Fermi surface and high mobility is favorable for pronounced transport response to the magnetic ordering. Furthermore, topological semimetals can possess interplay between the nontrivial topology of the electronic wave function and the magnetic ordering which leads to unusual transport properties such as band structure driven anomalous Hall effect. In this seminar, we will discuss the magnetotransport of magnetic nodal semimetals. In DyAgSb₂ and RAgGe (R = Ho and Dy) that show the magnetization plateau states, we observed the nonmonotonic field dependence of the longitudinal and transverse resistivities due to the field induced magnetic phase transitions and the associated multiple domain states. This response will be discussed in the context of the Drude model with field dependent mobility. In addition, we will present the unprecedentedly sharp angular response of magnetoresistance observed in CeAl(Ge_0.72Si_0.28) which originates from the Fermi surface mismatch across the magnetic domain boundary.

問合せ先　藤澤唯太、出田真一郎（放射光科学研究所）