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

• Published in: arXiv.org
• Main Authors: Bergeron, E Annelise, Sfigakis, F, Shi, Y, Nichols, George, Klipstein, P C, Elbaroudy, A, Walker, Sean M, Wasilewski, Z R, Baugh, J
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.01.2023
• Subjects: Carrier density; Contact resistance; Doping; Electron density; Heterostructures; Indium antimonide; Intermetallic compounds; Low resistance; Magnetic fields; Magnetoresistance; Magnetoresistivity; Modulation; Modulation doping; Physics - Mesoscale and Nanoscale Physics; Quantum wells; Spin-orbit interactions; Temperature dependence; Transport properties
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2209.08193

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.