Massive and topological surface states in tensile strained HgTe

Abstract

Magneto-transport measurements on gated high mobility heterostructures containing a 60 nm layer of tensile strained HgTe, a three-dimensional topological insulator, show well-developed Hall quantization from surface states both in the n- as well as in the p-type regime. While the n-type behavior is due to transport in the topological surface state of the material, we find from 8-orbital k.p calculations that the p-type transport results from massive Volkov-Pankratov states. Their formation prevents the Dirac point and thus the p-conducting topological surface state from being accessible in transport experiments. This interpretation is supported by low-field magneto-transport experiments demonstrating the coexistence of n-conducting topological surface states and p-conducting Volkov-Pankratov states at the relevant gate voltages.

15+5 pages, 5 figures; initially submitted version

References in corpus (3)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface

Cited by in corpus (4)

• Engineering topological phases in triple HgTe/CdTe quantum wells
• Observation of Weyl and Dirac fermions at smooth topological Volkov-Pankratov heterojunctions
• Quantum transport and mobility spectrum of topological carriers in (001) SnTe/PbTe heterojunctions
• Volkov-Pankratov states on the edge of a quantum spin Hall system