A parallel magnetic field driven confinement versus separation of charges in GaAs quantum well investigated by magneto-photovoltage and magneto-photoluminescence spectroscopy

Abstract

Opto-electronic properties of excitons under parallel and perpendicular magnetic field are investigated on various thickness of GaAs/AlGaAs quantum well. An analytical expression of diamagnetic energy under a parallel magnetic field is derived by solving the Schrödinger equation of exciton in quantum wells. The transformation underlying the solution of Schrödinger equation suggests that an in-plane separation between electron and hole may increase with an increasing parallel magnetic field, leading to a reduced coulomb interaction and slow radiative recombination rate. As a consequence of this, even in the absence of an external electrical bias, parallel magnetic field induces a chiral charge transportation across the hetero-interfaces of a quantum well, which gives rise to an increasing in-plane magneto-photovoltage signal. The present investigation provides a unique method to control the recombination and transportation of charges by the strength and orientation of a magnetic field.