2014/07/24 by Christoph Brüne, Brüne, Christoph, Cornelius Thienel +15
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Graphene research and applications #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1407.6537
openalex publication_date 2014/07/24 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
We report magnetotransport studies on a gated strained HgTe device. This\nmaterial is a threedimensional topological insulator and exclusively shows\nsurface state transport. Remarkably, the Landau level dispersion and the\naccuracy of the Hall quantization remain unchanged over a wide density range\n(3 \× 1011 cm-2 < n < 1 \× 1012 cm-2). This implies that\neven at large carrier densities the transport is surface state dominated, where\nbulk transport would have been expected to coexist already. Moreover, the\ndensity dependence of the Dirac-type quantum Hall effect allows to identify the\ncontributions from the individual surfaces. A k \⋅ p model can describe\nthe experiments, but only when assuming a steep band bending across the regions\nwhere the topological surface states are contained. This steep potential\noriginates from the specific screening properties of Dirac systems and causes\nthe gate voltage to influence the position of the Dirac points rather than that\nof the Fermi level.\n