Magnetic field and hopping effects on the current-voltage characteristics in aGaAs/Alx

Abstract

Adopting a simple one-band tight-binding Hamiltonian and using the diagrammatic techniques for nonequilibrium processes proposed by Keldysh, we investigate the resonant tunneling transport properties through GaAs/Al x Ga 1Ϫx As double-barrier heterostructures under the action of in-plane and parallel magnetic field. The in-plane magnetic field leads to a shift to higher bias and a diminishing of the intensity of the resonant tunneling peak in the characteristic curves of current versus voltage in good agreement with experimental results. Also, we have found that the diminishing of the hopping energy between nearest neighbors is caused by the same effects as the in-plane magnetic field on the current-voltage characteristics. On the other hand, we have found that the intensity of the resonant peaks increases when the magnetic field is applied parallel to the current direction, an expected result due to the increasing values of the magnitude of the hopping parameter with the magnetic field. Our results compare quite well with experimental reports.