Slow relaxation of magnetoresistance in doped p -GaAs/AlGaAs layers with partially filled upper Hubbard band

TL;DR

This paper reports on the slow relaxation of magnetoresistance in doped GaAs/AlGaAs quantum wells, attributed to magnetic-field-induced carrier redistribution in a Coulomb glass with partially filled Hubbard bands.

Contribution

It introduces the observation of slow magnetoresistance relaxation linked to carrier redistribution in a Coulomb glass with partially filled upper Hubbard bands in doped quantum wells.

Findings

Slow magnetoresistance relaxation observed in doped quantum wells.

Carrier redistribution driven by magnetic field affects the Coulomb glass.

Relaxation involves multi-particle processes in the charged centers.

Abstract

We observed slow relaxation of magnetoresistance in quantum well structures GaAs-AlGaAs with a selective doping of both wells and barrier regions which allowed partial filling of the upper Hubbard band. Such a behavior is explained as related to magnetic-field driven redistribution of the carriers between sites with different occupation numbers due to spin correlation on the doubly occupied centers. This redistribution, in its turn, leads to slow multi-particle relaxations in the Coulomb glass formed by the charged centers.