Demonstration of gate control of spin splitting in a high-mobility InAs/AlSb two-dimensional electron gas

Abstract

Control of zero-field spin splitting is realized in a dual-gated high-quality InAs-AlSb two-dimensional electron gas. Magnetotransport experiments showed clean Shubnikov--de Haas oscillations down to low magnetic fields, and the gate-tuned electron mobility exceeded $700\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{2}/\mathrm{V}\phantom{\rule{0.16em}{0ex}}\mathrm{s}$. A clear beating effect was observed in magnetoresistance oscillations at large potential asymmetry between gates. Beat patterns due to zero-field spin splitting and other classes of transverse magnetoresistance oscillations were distinguished by temperature-dependent magnetoresistance measurements. Analysis of the magnetoresistance oscillations indicated that the zero-field spin splitting could be tuned via the Rashba effect while keeping the two-dimensional electron gas charge density constant.