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arXiv · 2609.28795

Realization of Very High Mobility InAs Quantum Wells on InP Substrates Through Convex InAlAs Graded Buffer Optimization

Tyler Lindemann·Rojila Ghimire·Alejandro Alcaraz Ramirez·Ahmad Azizimanesh·Sergei Gronin·Ray Kallaher·Michael J. Manfra
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Abstract

Due to strong spin-orbit coupling, large Landé $g$-factor, and a highly transparent interface, the two-dimensional electron gas (2DEG) in InAs quantum wells provides an ideal platform for the exploration of topological superconductivity in hybrid semiconductor-superconductor heterostructures. Reduction of disorder in the semiconductor remains a primary challenge to the disambiguation of subtle interaction effects. Here we demonstrate very high mobility InAs 2DEGs grown on insulating InP substrates. Utilizing a convex compositional grading profile in an InAlAs metamorphic buffer we demonstrate InAs quantum wells with thickness greater than 10 nm without need of Ga-containing cladding layers. We examine structural and electrical transport properties of these heterostructures. Advances in the design of the metamorphic InAlAs buffer result in low-temperature electron mobility exceeding $1.7\times10^6$ cm$^2$ V$^{-1}$ s$^{-1}$ at 2DEG density $\leq3.2\times10^{11}$ cm$^{-2}$, the highest value yet reported for this material system.

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Tyler Lindemann, Rojila Ghimire, Alejandro Alcaraz Ramirez, Ahmad Azizimanesh, Sergei Gronin, Ray Kallaher, Michael J. Manfra. 2026-09-23. Realization of Very High Mobility InAs Quantum Wells on InP Substrates Through Convex InAlAs Graded Buffer Optimization. https://arxiv.org/abs/2609.28795

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