Quantum spin Hall insulators (QSHIs) based on HgTe and three-layer InAs/GaSb quantum wells (QWs) have comparable bulk band-gaps of about 10--18~meV. The former however features a band-gap vanishing with temperature, while the gap in InAs/GaSb QSHIs is rather temperature-independent.Here, we report on the realization of large inverted band-gap in strained three-layer InAs/GaInSb QWs. By temperature-dependent magnetotransport measurements of gated Hall bar devices, we extract a gap as high as 45 meV. Combining local and non-local measurements, we attribute the edge conductivity observed at temperatures up to 40 K to the topological edge channels with equilibration lengths of a few micrometers. Our findings pave the way toward manipulating edge transport at high temperatures in QW heterostructures.
@article{arxiv.2203.05977,
title = {Large inverted band-gap in strained three-layer InAs/GaInSb quantum wells},
author = {C. Avogadri and S. Gebert and S. S. Krishtopenko and I. Castillo and C. Consejo and S. Ruffenach and C. Roblin and C. Bray and Y. Krupko and S. Juillaguet and S. Contreras and S. Juillaguet and A. Wolf and F. Hartmann and S. Höfling and G. Boissier and J. B. Rodriguez and S. Nanot and E. Tournié and F. Teppe and B. Jouault},
journal= {arXiv preprint arXiv:2203.05977},
year = {2022}
}