Fizika Nizkikh Temperatur: Volume 43, Number 4 (April 2017), p. 537-545    ( to contents , go back )

Quantum capacitance of three-dimensional topological insulator based on a HgTe

D.A. Kozlov, D. Bauer, J. Ziegler, R. Fischer, M.L. Savchenko, Z.D. Kvon, N.N. Mikhailov, S.A. Dvoretsky, and D. Weiss E-mail: kvon@isp.nsc.ru

Received December 16, 2016

Abstract

We measured the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we shown that observed magnetocapacitance oscillations probe, in con-trast to magnetotransport, where all kinds of carriers con-tribute, primarily the top surface. Capacitance measure-ments constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi level. Using this technique we investigated the behavior of the Shubnikov–de Haas oscillations phase shift, usually asso-ciated with the Berry phase, for the single Dirac cone and its dependence from the Fermi energy.

PACS: 73.25.+i Surface conductivity and carrier phenomena;
PACS: 73.20.At Surface states, band structure, elec-tron density of states;
PACS: 73.43.–f Quantum Hall effects.

Key words: three-dimensional topological insulator, mercury telluride, magnetotransport, quantum Hall effect.

Published online: February 24, 2017

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ISSN: 0132-6414 (Print) | ISSN: 1816-0328 (Online)