Control of the electromagnetic environment of a quantum emitter by shaping the vacuum field in a coupled-cavity system

We propose a scheme for the ultrafast control of the emitter-field coupling rate in cavity quantum electrodynamics. This is achieved by the control of the vacuum field seen by the emitter through a modulation of the optical modes in a coupled-cavity structure. The scheme allows the on-off switching of the coupling rate without perturbing the emitter and without introducing frequency chirps on the emitted photons. It can be used to control the shape of single-photon pulses for high-fidelity quantum state transfer, to control Rabi oscillations, and as a gain-modulation method in lasers. We discuss two possible experimental implementations based on photonic crystal cavities and on microwave circuits

Control of the electromagnetic environment of a quantum emitter by shaping the vacuum field in a coupled-cavity system

We propose a scheme for the ultrafast control of the emitter-field coupling rate in cavity quantum electrodynamics. This is achieved by the control of the vacuum field seen by the emitter through a modulation of the optical modes in a coupled-cavity structure. The scheme allows the on-off switching of the coupling rate without perturbing the emitter and without introducing frequency chirps on the emitted photons. It can be used to control the shape of single-photon pulses for high-fidelity quantum state transfer, to control Rabi oscillations, and as a gain-modulation method in lasers. We discuss two possible experimental implementations based on photonic crystal cavities and on microwave circuits

Coupling of single quantum dots to photonic crystal cavities investigated by low-temperature scanning near-field optical microscopy

We report a study of single quantum dots inside photonic crystal cavities with a low-temperature scanning near-field optical microscope. The spatial maps of single excitonic lines from the quantum dot show the clear signature of coupling to the cavity modes for small detunings. We also show that the near-field tip can be used to control the exciton-photon coupling at the nanoscale. A general framework for the interpretation of near-field maps of single emitters in cavities is proposed

Integration of single-photon sources and detectors on GaAs

\u3cp\u3eQuantum photonic integrated circuits (QPICs) on a GaAs platform allow the generation, manipulation, routing, and detection of non-classical states of light, which could pave the way for quantum information processing based on photons. In this article, the prototype of a multi-functional QPIC is presented together with our recent achievements in terms of nanofabrication and integration of each component of the circuit. Photons are generated by excited InAs quantum dots (QDs) and routed through ridge waveguides towards photonic crystal cavities acting as filters. The filters with a transmission of 20% and free spectral range ≥66 nm are able to select a single excitonic line out of the complex emission spectra of the QDs. The QD luminescence can be measured by on-chip superconducting single photon detectors made of niobium nitride (NbN) nanowires patterned on top of a suspended nanobeam, reaching a device quantum efficiency up to 28%. Moreover, two electrically independent detectors are integrated on top of the same nanobeam, resulting in a very compact autocorrelator for on-chip g\u3csup\u3e(2)\u3c/sup\u3e(τ) measurements.\u3c/p\u3