The effect of hydrostatic pressure on the binding energy and diamagnetic susceptibility of a laser dressed donor impurity in a GaAs/GaAlAs nanowire superlattice

Abstract

In this paper the effects of hydrostatic pressure and laser radiation on the binding energy and diamagnetic susceptibility of an off-center hydrogenic donor impurity in a nanowire superlattice (NWSL) are studied. The energy eigenvalues and corresponding wave functions of ground and first excited states are numerically computed using finite difference method for a NWSL with circular cross-section which involved an array of spherical quantum dots (QDs). The numerical results show that oscillatory behaviors appear in binding energies and diamagnetic susceptibilities of ground and first excited states as impurity shifts away from center of QDs. Maximum values of ground state binding energy (first excited state binding energy) occur when impurity is located at the center of QDs (at the center of barriers). Additionally, binding energies of ground and first excited states shift towards higher (lower) energies as pressure (laser radiation) increases. An opposite behavior is observed for absolute value of diamagnetic susceptibility as pressure or laser radiation increases. Also, as the QDs’ volume increases the binding energies (I) decrease or (II) increase, reach maximum values and then decrease; which strongly depend on the position of impurity.