Electric bias-controlled switching of magnetization of ferrimagnetically coupled Mn delta-layers in a GaAs-AlGaAs quantum well

Abstract

We suggest a design of an artificial ferrimagnet consisting of two Mndoped delta layers with different concentrations placed in a GaAs-AlGaAs quantum well and coupled via extra holes in the well.• We analyze a scenario of the magnetization switching in the artificial ferrimagnet realized via heating the holes by picosecond electric bias pulse which facilitates exchange scattering of the holes on Mn ions. AbstractWe suggest a model of synthetic ferrimagnetic semiconductor structure based on GaAs-AlGaAs quantum well doped by two Mn delta-layers. The coupling between the delta-layers is mediated by extra holes, and can be switched between ferro-and antiferromagnetic one by gating the structure. A proper choice of Mn concentrations in the delta-layers and of local degree of disorder enables fabrication of a ferrimagnetic structure supporting ultrafast switching of magnetization by short pulses of electric bias without an external magnetic field. The switching mechanism in the structure relies on kinetic spin exchange between the two delta-layers which is mediated by exchange scattering of electric-pulse heated holes by magnetic ions within the layers. Owing to specific interplay between characteristics of the exchange scattering, spin decay times, and the heat withdraw in the suggested synthetic ferrimagnetic semiconductor, the necessary parameters of electric-bias pulse are within the technologically accessible range, and do not contradict typical thermal kinetics of semiconductor structures.