Quantum transport in high-quality shallow InSb quantum wells

Abstract

InSb is one of the promising candidates to realize a topological state through proximity induced superconductivity in a material with strong spin-orbit interactions. In two-dimensional systems, thin barriers are needed to allow strong coupling between superconductors and semiconductors. However, it is still challenging to obtain a high-quality InSb two-dimensional electron gas in quantum wells close to the surface. Here we report on a molecular beam epitaxy grown heterostructure of InSb quantum wells with substrate-side Si-doping and ultra-thin InAlSb (5 nm, 25 nm, and 50 nm) barriers to the surface. We demonstrate that the carrier densities in these quantum wells are gate-tunable and electron mobilities up to 350,000 $\mathrm{c}{\mathrm{m}}^2(\mathrm{Vs}{)}^{-1}$ are extracted from magneto-transport measurements. Furthermore, from temperature-dependent magneto-resistance measurements, we extract an effective mass of 0.02 $m_0$ and find a Zeeman splitting compatible with the expected g-factor.

Zijin Lei and Christian A. Lehner contributed equally to this work. For Supplementary Materials, please download the source files

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Cited by in corpus (2)

• Strong and tunable spin-orbit interaction in a single crystalline InSb nanosheet
• Gate-defined Quantum Point Contact in an InSb Two-dimensional Electron Gas