A spintronic source of circularly polarized single photons

摘要

We present a spintronic single photon source which emits circularly polarizedlight, where the helicity is determined by an applied magnetic field. Photonsare emitted from an InGaAs quantum dot inside an electrically operated spinlight-emitting diode, which comprises the diluted magnetic semiconductorZnMnSe. The circular polarization degree of the emitted light is high, reaching83% at an applied magnetic field of 2T and 96% at 6 T. Autocorrelation tracesrecorded in pulsed operation mode prove the emitted light to be antibunched.The two circular polarization states could be used for representing quantumstates |0> and |1> in quantum cryptography implementations.