Electron States in a Rectangular Quantum Well with Tilted Magnetic Field

Abstract

The effect of a tilted magnetic field in a rectangular symmetrical quantum well formed by GaAs/AlxGa1-xAs is studied using perturbation theory. The single electron energystates and hence the resonance energies are calculated as functions of the magnetic field. The energies corresponding to the cyclotron resonance, intersubband and combined intersubband-cyclotron resonance in tilted magnetic fields are obtained. We have also calculated the oscillator strengths and cyclotron mass ratios for different magnetic fields. The cyclotron resonance and combined resonance are observed only in magnetic fields B ≥ 3T. The diamagnetic shift in the intersubband resonance and the depolarisation shift of the diamagnetically shifted intersubband resonance are calculated for various values of the tilted magnetic field. The depolarisation shift increases only for B ≥ 1T and the intersubband resonance oscillator strength starts decreasing for B ≥ 1T. The oscillator strengths are also calculated as functions of the well width and the tilt angle. While the intersubband resonance is possible in very narrow wells, the cyclotron resonance and the combined intersubband-cyclotron resonance appear only for well width L ≥ 300Å, when the tilt angle is 45° and the field strength is 3T.