Field effect two-dimensional electron gases in modulation-doped InSb surface quantum wells

Abstract

We report on transport characteristics of field effect two-dimensional electron gases (2DEG) in surface indium antimonide quantum wells. The topmost 5 nm of the 30 nm wide quantum well is doped and shown to promote the formation of reliable, low resistance Ohmic contacts to surface InSb 2DEGs. High quality single-subband magnetotransport with clear quantized integer quantum Hall plateaus are observed to filling factor $\nu =1$ in magnetic fields of up to $B=18$ T. We show that the electron density is gate-tunable, reproducible, and stable from pinch-off to 4$\times 10^{11}$ cm${}^{-2}$, and peak mobilities exceed 24,000 cm${}^2$/Vs. Large Rashba spin-orbit coefficients up to 110 meV$\cdot$Å are obtained through weak anti-localization measurements. An effective mass of 0.019$m_e$ is determined from temperature-dependent magnetoresistance measurements, and a g-factor of 41 at a density of 3.6$\times 10^{11}$ cm${}^{-2}$ is obtained from coincidence measurements in tilted magnetic fields. By comparing two heterostructures with and without a delta-doped layer beneath the quantum well, we find that the carrier density is stable with time when doping in the ternary Al${}_{0.1}$In${}_{0.9}$Sb barrier is not present. Finally, the effect of modulation doping on structural asymmetry between the two heterostructures is characterized.

Main text 7 pages 4 figures; Supplemental 17 pages 7 figures; added bandstructure simulations and MBE growth details, otherwise minor modifications to previous version

References in corpus (7)

• Quantized conductance and large g-factor anisotropy in InSb quantum point contacts
• InSbAs two-dimensional electron gases as a platform for topological superconductivity
• Gate-tunable high mobility remote-doped InSb/In_{1-x}Al_{x}Sb quantum well heterostructures
• Quantum transport in high-quality shallow InSb quantum wells
• Gate-defined Quantum Point Contact in an InSb Two-dimensional Electron Gas
• Non-adiabatic single-electron pump in a dopant-free GaAs/AlGaAs 2DEG
• Field-effect-induced two-dimensional electron gas utilizing modulation doping for improved ohmic contacts

Cited by in corpus (1)

• High transparency induced superconductivity in field effect two-dimensional electron gases in undoped InAs/AlGaSb surface quantum wells