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arXiv · 2002.12248

Non-trivial quantum magnetotransport oscillations in pure and robust topological $\alpha$-Sn films

Ivan Madarevic·Niels Claessens·Aleksandr Seliverstov·Chris Van Haesendonck·Margriet J. Van Bael
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Abstract

We report experimental evidence of topological Dirac fermion charge carriers in pure and robust $\alpha$-Sn films grown on InSb substrates. This evidence was acquired using standard macroscopic four-point contact resistance measurements, conducted on uncapped films with a significantly reduced bulk mobility. We analyzed and compared electrical characteristics of the constituting components of the $\alpha$-Sn/InSb sample, and propose a three-band drift velocity model accordingly. A surface band, with low carrier density and high mobility, is identified as the origin of the observed Shubnikov -- de Haas oscillations. The analysis of these quantum oscillations results in a non-trivial value of the phase shift $\gamma =0$, characteristic for topologically protected Dirac fermions. For the same uncapped samples we estimate the momentum relaxation time $\tau\approx 300\ \mathrm{fs}$, which is significantly larger in comparison with the previous reports on grown $\alpha$-Sn films.

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Ivan Madarevic, Niels Claessens, Aleksandr Seliverstov, Chris Van Haesendonck, Margriet J. Van Bael. 2020-02-27. Non-trivial quantum magnetotransport oscillations in pure and robust topological $\alpha$-Sn films. https://arxiv.org/abs/2002.12248

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