Pressure effects in GaAs/AlGaAs heterostructures

Abstract

The trends in the pressure dependence of the electronic transmission in single- and multiple-barrier GaAs/AlGaAs heterostructures are calculated using a microscopic pseudopotential method. Electric effects are also included in our model. We find that in single-barrier systems the pressure induced direct to indirect band-gap transition alone does not affect the electron tunneling properties. It is only when the barrier’s X minimum is lowered below the electron energy that significant changes are found in the electron transmission. In a multiple-barrier system the lowering of the barrier X minimum due to the applied pressure and bias effectively pushes up the Γ resonant levels in the GaAs such that a clear negative differential resistance signal is lost.