Widely Tunable Berry Curvature in the Magnetic Semimetal Cr1+ δ Te2.

Academic Article

Abstract

  • Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr1+ δ Te2 is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent studies have explored real-space Berry curvature effects, similar considerations of momentum-space Berry curvature are lacking. Here, the electronic structure and transport properties of epitaxial Cr1+ δ Te2 thin films are systematically investigated over a range of doping, δ (0.33 - 0.71). Spectroscopic experiments reveal the presence of a characteristic semi-metallic band region, which shows a rigid like energy shift with δ. Transport experiments show that the intrinsic component of the anomalous Hall effect (AHE) is sizable and undergoes a sign flip across δ. Finally, density functional theory calculations establish a link between the doping evolution of the band structure and AHE: the AHE sign flip is shown to emerge from the sign change of the Berry curvature, as the semi-metallic band region crosses the Fermi energy. These findings underscore the increasing relevance of momentum-space Berry curvature in magnetic TMDs and provide a unique platform for intertwining topological physics in real and momentum spaces.
  • Authors

  • Fujisawa, Yuita
  • Pardo-Almanza, Markel
  • Hsu, Chia-Hsiu
  • Mohamed, Atwa
  • Yamagami, Kohei
  • Krishnadas, Anjana
  • Chang, Guoqing
  • Chuang, Feng-Chuan
  • Khoo, Khoong Hong
  • Zang, Jiadong
  • Soumyanarayanan, Anjan
  • Okada, Yoshinori
  • Status

    Publication Date

  • March 2023
  • Published In

  • Advanced Materials  Journal
  • Keywords

  • ARPES
  • Berry curvature
  • anomalous Hall effects
  • low dimensional materials
  • magnetic semimetals
  • Digital Object Identifier (doi)

    Pubmed Id

  • 36642840
  • Start Page

  • e2207121
  • Volume

  • 35
  • Issue

  • 12