Optical orientation of particles with a random g-factor in semiconductor nanostructures

Abstract

In real quasi-two-dimensional semiconductor nanostructures (quantum wells, quantum dots), the transverse g-factor of holes is a stochastic quantity. This fact should be taken into account in analyzing the optical orientation and Hanle effect of holes. The Hall effect for an ensemble of particles with a “random” g-factor has been treated theoretically. In the case where the spin relaxation time of a hole with a characteristic g-factor is shorter than the hole lifetime, there can occur a narrowing of the depolarization contour and an increase in its amplitude. In the opposite case of long spin relaxation times (trions in quantum dots), a formula has been derived, which generalizes the previously obtained result to the case of an arbitrary tilt angle of the magnetic field with respect to the plane of the layer (Hanle effect in the tilted form).