二维斯格明子晶格的拓扑能斯特效应

Topological Nernst Effect of the Two-Dimensional Skyrmion Lattice.

作者信息

Hirschberger Max, Spitz Leonie, Nomoto Takuya, Kurumaji Takashi, Gao Shang, Masell Jan, Nakajima Taro, Kikkawa Akiko, Yamasaki Yuichi, Sagayama Hajime, Nakao Hironori, Taguchi Yasujiro, Arita Ryotaro, Arima Taka-Hisa, Tokura Yoshinori

机构信息

RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.

Department of Applied Physics and Quantum-Phase Electronics Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.

出版信息

Phys Rev Lett. 2020 Aug 14;125(7):076602. doi: 10.1103/PhysRevLett.125.076602.

DOI:10.1103/PhysRevLett.125.076602

PMID:32857583

Abstract

The topological Hall effect (THE) and its thermoelectric counterpart, the topological Nernst effect (TNE), are hallmarks of the skyrmion lattice phase (SkL). We observed the giant TNE of the SkL in centrosymmetric Gd_{2}PdSi_{3}, comparable in magnitude to the largest anomalous Nernst signals in ferromagnets. Significant enhancement (suppression) of the THE occurs when doping electrons (holes) to Gd_{2}PdSi_{3}. On the electron-doped side, the topological Hall conductivity approaches the characteristic threshold ∼1000 (Ω cm)^{-1} for the intrinsic regime. We use the filling-controlled samples to confirm Mott's relation between TNE and THE and discuss the importance of Gd-5d orbitals for transport in this compound.

摘要

拓扑霍尔效应（THE）及其热电对应物拓扑能斯特效应（TNE）是斯格明子晶格相（SkL）的标志。我们在中心对称的Gd₂PdSi₃中观测到了SkL的巨大TNE，其大小与铁磁体中最大的反常能斯特信号相当。当向Gd₂PdSi₃中掺杂电子（空穴）时，THE会显著增强（抑制）。在电子掺杂一侧，拓扑霍尔电导率接近本征态的特征阈值~1000（Ω·cm）⁻¹。我们使用填充控制的样品来证实TNE和THE之间的莫特关系，并讨论Gd-5d轨道在该化合物输运中的重要性。