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

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.