Oleksandr Kyriienko

Optomechanics with cavity polaritons: dissipative coupling and unconventional bistability.

We study a hybrid system formed from an optomechanical resonator and a cavity mode strongly coupled to an excitonic transition inside a quantum well. We show that due to the mixing of cavity photon and exciton states, the emergent quasiparticles-polaritons-possess coupling to the mechanical mode of both a dispersive and dissipative nature. We calculate the occupancies of polariton modes and reveal bistable behavior, which deviates from conventional Kerr nonlinearity or dispersive coupling cases due to the dissipative coupling. The described system serves as a good candidate for future polaritonic devices.

Tunable single-photon emission from dipolaritons

We study a system comprising of a double quantum well embedded in a micropillar optical cavity, where strong coupling between a direct exciton, an indirect exciton, and a cavity photon is achieved. We show that the resulting hybrid quasiparticles---dipolaritons---can induce strong photon correlations and lead to antibunched behavior of the cavity output field. The origin of the observed single-photon emission is attributed to unconventional photon blockade. We find that the second-order equal-time correlation function

Superradiant terahertz emission by dipolaritons.

{g}^{(2)}(0)

Triggered single-photon emitters based on stimulated parametric scattering in weakly nonlinear systems

can be tuned over a large range by using an electric field applied to the structure, or by changing the frequency of the pump. This allows for on-the-flight control of cavity output properties and is important for the future generation of tunable single-photon-emission sources.

Bistability in microcavities with incoherent optical or electrical excitation

Dipolaritons are mixed light-matter quasiparticles formed in double quantum wells embedded in microcavities. Because of resonant coupling between direct and indirect excitons via electronic tunneling, dipolaritons possess large dipole moments. Resonant excitation of the cavity mode by a short pulse of light induces oscillations of the indirect exciton density with a characteristic frequency of Rabi flopping. This results in oscillations of a classical Hertz dipole array which generate supperradiant emission on a terahertz (THz) frequency. The resulting THz signal may be enhanced using the supplementary THz cavity in the weak coupling regime.

Exciton-polariton quantum gates based on continuous variables

We introduce a scheme of single-photon emission based on four-wave mixing in a three mode system with weak Kerr-type nonlinearity. A highly populated lower energy mode results in strong stimulated scattering of particle pairs out of the central mode, which consequently limits the central mode occupation. Thus, the system can be reduced to a

Terahertz laser based on dipolaritons

{\ensuremath{\chi}}^{(2)}

Spin dynamics of cold exciton condensates.

nonlinear medium with greatly enhanced interaction constant. As a model setup we consider dipolaritons in semiconductor microcavities. Using the master equation approach we show strong antibunching under continuous-wave pump, which largely exceeds the conventional blockade mechanism. Finally, using a pulsed excitation we demonstrate theoretically a triggered single-photon emitter in a weakly nonlinear system with

Continuous terahertz emission from dipolaritons

33%

One-dimensional Van Hove polaritons.

emission probability.