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

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.