Deterministic light matter coupling with single quantum dots

In 1946, E. M. Purcell predicted that the radiative lifetime of an emitter is not an intrinsic property but can be modified by structuring the surrounding electromagnetic field. By inserting a semiconductor quantum dot (QD) in an optical cavity, one can accelerate or inhibit its spontaneous emission. In the present article, we show that the QD spontaneous emission can be deterministically controlled to fabricate bright sources of quantum light.QDs in cavities: basics, motivation, first demonstrationsLight-matter couplingWe note the ground state of the QD and its excited state. For a cavity mode close to resonance with the QD optical transition, we consider only the states with 0 or 1 photon in the cavity mode. The states it are coupled through light–matter interaction, with a constant where ic> the electric field at the QD position.Each of the states are also coupled to continua of states: continuum ofthe free-space optical mode, phonons of the semiconductor matrix, etc.Here, we consider only the coupling to the continuum of the free-space optical mode, related to the cavity losses, with a constant When the photon emitted by the recombination of an exciton efficiently escapes outside the cavity. The QD optical transition radiative recombination rate can be accelerated (Purcell effect) or inhibited.