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 cm2(Vs)−1 are extracted from magneto-transport measurements. Furthermore, from temperature-dependent magneto-resistance measurements, we extract an effective mass of 0.02 m0 and find a Zeeman splitting compatible with the expected g-factor.
@article{arxiv.1904.00828,
title = {Quantum transport in high-quality shallow InSb quantum wells},
author = {Zijin Lei and Christian A. Lehner and Erik Cheah and Matija Karalic and Christopher Mittag and Luca Alt and Jan Scharnetzky and Werner Wegscheider and Thomas Ihn and Klaus Ensslin},
journal= {arXiv preprint arXiv:1904.00828},
year = {2019}
}
Comments
Zijin Lei and Christian A. Lehner contributed equally to this work. For Supplementary Materials, please download the source files