2020/02/27 by Ivan Mađarević, Niels Claessens, Madarevic, Ivan +7
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2002.12248
openalex publication_date 2020/02/27 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
We report experimental evidence of topological Dirac fermion charge carriers in pure and robust α-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 α-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 γ=0, characteristic for topologically protected Dirac fermions. For the same uncapped samples we estimate the momentum relaxation time τ≈ 300 fs, which is significantly larger in comparison with the previous reports on grown α-Sn films.