Near-surface InAs two-dimensional electron gas on a GaAs substrate: Characterization and superconducting proximity effect

We have studied a near-surface two-dimensional electron gas based on an InAs quantum well on a GaAs substrate. In devices without a dielectric layer we estimated large electron mobilities on the order of 10(5) cm(2)/Vs. We have observed quantized conductance in a quantum point contact, and determined the g factor. Using samples with an epitaxial Al layer, we defined multiple Josephson junctions and found the critical current to be gate tunable. Based on multiple Andreev reflections the semiconductor-superconductor interface is transparent, with an induced gap of 125 mu eV. Our results suggest that this InAs system is a viable platform for use in hybrid topological superconductor devices.

Automated summary

We studied a near-surface two-dimensional electron gas based on an InAs quantum well on a GaAs substrate. High electron mobilities were estimated in devices without a dielectric layer. We observed quantized conductance in a quantum point contact and determined the g factor. Multiple Josephson junctions were defined using samples with an epitaxial Al layer, and the critical current was found to be gate tunable. The semiconductor-superconductor interface was transparent based on multiple Andreev reflections, with an induced gap of 125 mu eV. Our results suggest that this InAs system is a viable platform for use in hybrid topological superconductor devices.