Quantum memory and all-optical switching in positive charged quantum dots via Zeeman coherent oscillations

Linear and nonlinear properties in an ensemble of single-hole spin InGaAs/GaAs quantum dots are theoretically studied. The application of a DC magnetic field in the semiconductor growth plane induces a Zeeman splitting of the hole levels which can be modeled like a four-level atom in the X-type configuration. All-optical and magneto-optical switching of a weak probe field are shown to be feasible in this system either by changing the Rabi frequency of an auxiliary control field or by changing the magnitude of the external magnetic field. We analyze the feasibility to store and release a weak pulse from the medium resulting from Zeeman coherent oscillations, thus the system is expected to be useful to develop a variable semiconductor optical buffer.