Optical orientation of a single Mn spin in a quantum dot: Role of carrier spin relaxation

Abstract: In order to explain the recently observed phenomenon of optical orientation of a single Mn spin residing inside a quantum dot, a process of Mn spin relaxation with characteristic timescale of tens of nanoseconds had been invoked. We show that after taking into account the mixing of states of the exciton and the Mn spin (due to the sp-d exchange interaction), the observed Mn optical orientation time can be explained by invoking only the processes of carrier spin relaxation.