Gating of two-dimensional electron systems in InGaAs/InAlAs heterostructures: the role of the intrinsic InAlAs deep donor defects

TL;DR

This paper investigates how intrinsic deep donor defects in InGaAs/InAlAs heterostructures influence their electrostatic response to gating, providing insights for optimizing spin-orbitronic device functionalities.

Contribution

It introduces a phenomenological model linking heterostructure design, especially indium concentration, to gate response, emphasizing the role of deep donor defects in electrostatic behavior.

Findings

Deep donor defects affect charge trapping and tunneling.

Metastable electrostatic states reduce capacitive coupling.

Gate strategies can achieve classical field effect control.

Abstract

We present an analysis of gated InGaAs/InAlAs heterostructures, a device platform to realize spinorbitronic functionalities in semiconductors. The phenomenological model deduced from our magnetotransport experiments allows us to correlate the gate response of the studied two-dimensional electron systems to heterostructure design parameters, in particular the indium concentration. We explain the occurrence of metastable electrostatic configurations showing reduced capacitive coupling and provide gate operation strategies to reach classical field effect control in such heterostructures. Our study highlights the role of the intrinsic InAlAs deep donor defects, as they govern the dynamics of the electrostatic response to gate voltage variations through charge trapping and unintentional tunneling.