The influence of δ-〈Mn〉-layer's magnetization on polarization of photoluminescence of quantum well in singular and vicinal InGaAs/GaAs/δ-〈Mn〉 heterostructures

Abstract

Magneto-optical properties and spin dynamics in a p-type GaAs-based heterostructures containing an InGaAs quantum well and 2 nm thick GaAs layer doped with 5 at. % Mn (GaAs:Mn) on flat and vicinal substrates were studied between 2 and 300 K. A significant enhancement of photoluminescence circular polarization Pc = 15 % was found at temperatures T < 30 K. In the non-magnetic quantum well Pc = 0 %. The polarization of the InGaAs quantum well photoluminescence follows the temperature dependence of the GaAs:Mn layer magnetization. Two types of ferromagnetism were found. In the heterostructures grown on the flat substrate parallel to the (001) GaAs plane the magnetization obeys the Bloch T 3/2 temperature dependence while for the structures grown on the vicinal surface (disoriented by 3°) the magnetization follows percolation dependence. The later is attributed to the formation of strongly disordered islands of GaAs:Mn.