Enhancement of the anomalous Hall effect by distorting the Kagome lattice in an antiferromagnetic material

• 成果类型: Article
• 署名作者: Roychowdhury, Subhajit; Samanta, Kartik; Singh, Sukriti; Schnelle, Walter; Zhang, Yang; Noky, Jonathan; Vergniory, Maia G.; Shekhar, Chandra; Felser, Claudia
• 署名单位: Max Planck Society; Indian Institute of Science Education & Research (IISER) - Bhopal; University of Tennessee System; University of Tennessee Knoxville; University of Tennessee System; University of Tennessee Knoxville
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9996
• DOI: 10.1073/pnas.2401970121
• 发表日期: 2024-07-23
• 关键词: spin ice state; noncollinear phase; ORDER

摘要

In topological magnetic materials, the topology of the electronic wave function is strongly coupled to the structure of the magnetic order. In general, ferromagnetic Weyl semimetals generate a strong anomalous Hall conductivity (AHC) due to a large Berry curvature that scales with their magnetization. In contrast, a comparatively small AHC is observed in noncollinear antiferromagnets. We investigated HoAgGe, an antiferromagnetic (AFM) Kagome spin-ice compound, which crystallizes in a hexagonal ZrNiAl-type structure in which Ho atoms are arranged in a distorted Kagome lattice, forming an intermetallic Kagome spin-ice state in the ab-plane. It exhibits a large topological Hall resistivity of similar to 1.6 mu Omega-cm at 2.0 K in a field of similar to 3 T owing to the noncoplanar structure. Interestingly, a total AHC of 2,800 Omega(-1) cm(-1) is observed at similar to 45 K, i.e., 4 T-N, which is quite unusual and goes beyond the normal expectation considering HoAgGe as an AFM Kagome spin-ice compound with a T-N of similar to 11 K. We demonstrate further that the AHC below T-N results from the nonvanishing Berry curvature generated by the formation of Weyl points under the influence of the external magnetic field, while the skew scattering led by Kagome spins dominates above the T-N. These results offer a unique opportunity to study frustration in AFM Kagome lattice compounds.