Universal Conductance Fluctuations in a MnBi2Te4 Thin Film

Molly P Andersen; Evgeny Mikheev; Ilan T Rosen; Lixuan Tai; Peng Zhang; Kang L Wang; Marc A Kastner; David Goldhaber-Gordon

doi:10.1021/acs.nanolett.3c02932

Universal Conductance Fluctuations in a MnBi₂Te₄ Thin Film

Nano Lett. 2023 Dec 13;23(23):10802-10810. doi: 10.1021/acs.nanolett.3c02932. Epub 2023 Nov 29.

Authors

Molly P Andersen^{1

2

3}, Evgeny Mikheev^{2

4

3}, Ilan T Rosen^{2

3

5

6}, Lixuan Tai⁷, Peng Zhang⁷, Kang L Wang⁷, Marc A Kastner^{2

4

8}, David Goldhaber-Gordon^{2

4}

Affiliations

¹ Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States.
² Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States.
³ Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221, United States.
⁴ Department of Physics, Stanford University, Stanford, California 94305, United States.
⁵ Department of Applied Physics, Stanford University, Stanford, California 94305, United States.
⁶ Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
⁷ Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States.
⁸ Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

PMID: 38029283
DOI: 10.1021/acs.nanolett.3c02932

Abstract

Quantum coherence of electrons can produce striking behaviors in mesoscopic conductors. Although magnetic order can also strongly affect transport, the combination of coherence and magnetic order has been largely unexplored. Here, we examine quantum coherence-driven universal conductance fluctuations in the antiferromagnetic, canted antiferromagnetic, and ferromagnetic phases of a thin film of the topological material MnBi₂Te₄. In each magnetic phase, we extract a charge carrier phase coherence length of about 100 nm. The conductance magnetofingerprint is repeatable when sweeping applied magnetic field within one magnetic phase. Surprisingly, in the antiferromagnetic and canted antiferromagnetic phases, but not in the ferromagnetic phase, the magnetofingerprint depends on the direction of the field sweep. To explain our observations, we suggest that conductance fluctuation measurements are sensitive to the motion and nucleation of magnetic domain walls in MnBi₂Te₄.

Keywords: magnetic domains; magnetic topological insulators; quantum coherence; universal conductance fluctuations.