A quantum dot based bright source of entangled photon pairs operating at 53 K

Abstract

The exciton and biexciton lines of a single quantum dot are deterministically coupled to the optical modes of a photonic molecule. The resonance between the quantum dot emission lines and the molecule cavity modes is reached at 53 K. The device operates as a very bright source of entangled photon pairs, with an extraction efficiency of 40% for each photon of the pair. Our measurements show that the use of Purcell effect allows to quench the exciton spin relaxation during the radiative cascade, at 53 K and at high excitation power.