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Topologically nontrivial magnetism in Cr<sub>2</sub>Te<sub>3</sub> ultrathin films

ORAL

Abstract

Transition metal chalcogenides are versatile for realizing topological phenomena. Quasi 2D Cr2Te3 MBE films enable control over charge/spin degrees of freedom, leveraged by strain tunability at the substrate/film interface. Cr2Te3 films display perpendicular magnetic anisotropy with a Curie temperature of ~ 160 K for thickness of 20 unit cells, whose structure and magnetic properties are examined by transmission electron microscopy, polarized neutron reflectometry and scanning tunneling microscopy. This is accompanied by rich magnetotransport properties: apart from the ordinary Hall effect with linear field dependence, the anomalous Hall effect manifests a unique temperature-dependent sign reversal. Novel topological Hall effect (THE) appears, related to the emergence of magnetic skyrmions, nanometer-sized quasiparticles with topological spin textures. The magnitude of the THE is tunable via interface strain that can be varied by film thickness and choice of substrate (Al2O3 and SrTiO3). The effective interface-driven tunability of non-coplanar spin textures in Cr2Te3 ultrathin films offers new opportunities for spintronics.

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Presenters

  • Hang Chi

    Massachusetts Institute of Technology, Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

Authors

  • Hang Chi

    Massachusetts Institute of Technology, Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Yunbo Ou

    Massachusetts Institute of Technology, Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology

  • Tim B. Eldred

    North Carolina State University

  • Wenpei Gao

    University of California, Irvine, North Carolina State University

  • Valeria Lauter

    Oak Ridge National Lab, Oak Ridge National Laboratory

  • Michael Dreyer

    University of Maryland, College Park, University of Maryland, Physics, University of Maryland, Department of Physics, University of Maryland

  • Robert E Butera

    Laboratory for Physical Sciences

  • George J. de Coster

    U.S. Army CCDC Army Research Laboratory, Sensors & Electron Devices Directorate, U.S. Army Research Laboratory

  • Charles Rong

    U.S. Army CCDC Army Research Laboratory

  • Donald E Heiman

    Northeastern University

  • Jagadeesh S Moodera

    Massachusetts Institute of Technology, Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics,, Massachusetts Institute of Technology, Physics, Massachusetts Institute of Technology, Department of Physics, Massachusetts Institute of Technology