  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.
