title: Probing Quantum Capacitance in a 3D Topological Insulator.
abstract: We measure 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 show that observed magnetocapacitance oscillations probe-in contrast to magnetotransport-primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy.
authors.affiliation: A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090, Russia.|Novosibirsk State University, Novosibirsk 630090, Russia.|Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: D A
authors.initials: DA
authors.lastname: Kozlov
authors.affiliation: Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Bauer
authors.affiliation: Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Ziegler
authors.affiliation: Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Fischer
authors.affiliation: A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090, Russia.|Novosibirsk State University, Novosibirsk 630090, Russia.
authors.forename: M L
authors.initials: ML
authors.lastname: Savchenko
authors.affiliation: A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090, Russia.|Novosibirsk State University, Novosibirsk 630090, Russia.
authors.forename: Z D
authors.initials: ZD
authors.lastname: Kvon
authors.affiliation: A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090, Russia.
authors.forename: N N
authors.initials: NN
authors.lastname: Mikhailov
authors.affiliation: A. V. Rzhanov Institute of Semiconductor Physics, Novosibirsk 630090, Russia.
authors.forename: S A
authors.initials: SA
authors.lastname: Dvoretsky
authors.affiliation: Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Weiss