Gate-tunable ferromagnetism in epitaxially grown Dirac semimetal-ferromagnetic semiconductor heterostructures

ORAL

Abstract

The coexistence of time-reversal and inversion symmetry in Dirac semimetals (DSMs) is responsible for topologically protected, spin-degenerate bulk states with Dirac dispersion. Breaking either of these symmetries results in a Weyl semimetal with broken Kramers degeneracy. This motivates the development of materials platforms wherein an external parameter (such as a gate voltage) is used to break a relevant symmetry (such as time-reversal) in a DSM. We explore this concept by using molecular beam epitaxy to interface a canonical DSM, Cd3As2, with a ferromagnetic semiconductor, (In,Mn)As, with perpendicular magnetic anisotropy. Measurements of the anomalous Hall effect (AHE) in top-gated Cd3As2/(In,Mn)As devices show that the ferromagnetic Curie temperature is highly gate-tunable. We map out the AHE in these heterostructures as a function of sample structure and chemical potential. Model Hamiltonian calculations, supported by density functional theory, provide insight into the observed behavior.

* This project was supported in part by the Institute for Quantum Matter under DOE EFRC Grant No. DESC0019331 and the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE1255832

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Publication: "Gate-tunable ferromagnetism in epitaxially grown Dirac semimetal-ferromagnetic semiconductor heterostructures" in progress

Presenters

  • Emma K Steinebronn

    Pennsylvania State University

Authors

  • Emma K Steinebronn

    Pennsylvania State University

  • Saurav Islam

    Pennsylvania State University

  • Run Xiao

    Pennsylvania State University

  • Wilson J Yanez Parreno

    Pennsylvania State University, University of California Santa Barbara

  • Yongxi Ou

    The Pennsylvania State University

  • Supriya Ghosh

    University of Minnesota

  • Juan Chamorro

    University of California, Santa Barbara

  • Tyrel M McQueen

    Johns Hopkins University, Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Chaoxing Liu

    Pennsylvania State University, The Pennsylvania State University

  • Andre Mkhoyan

    University of Minnesota, University of Minnesota, Twin Cities

  • Nitin Samarth

    Pennsylvania State University