We theoretically study the polariton multistability in a solid state based optomechanical resonator embedded with a quantum well and a χ (2) second order nonlinear medium. The excitonic transition inside the quantum well is strongly coupled to the optical cavity mode. The polariton formed due to the mixing of cavity photons and exciton states are coupled to the mechanical mode which gives rise to the bistable behavior. A transition from bistability to tristability occurs in the presence of a strong χ (2) nonlinearity. Switching between bistability and tristability can also be controlled using exciton-cavity and optomechanical coupling making the system highly tunable. Tristability appears at low input power making it a suitable candidate for polaritonic devices which requires low input power.

We theoretically explore optical bistability for possible signature of all optical switching and their performance in a hybrid quantum optomechanical system comprising of two semiconductor microcavity coupled optically. One of the cavity is driven by an external optical pump laser while the second cavity which contains a quantum dot is indirectly driven by light transmitted from the first cavity. The generated bistable behavior due to optomechanical nonlinearity shows a typical optical switching behavior and it can be controlled by changing the laser power, QD cavity coupling, rocking parameter, and the optomechanical coupling.A clear signature of energy exchange between mechanical optical modes is visible from the mechanical displacement spectrum. These results suggest that the present system can be used for an application in sensitive optical switch and optical sensors.

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The recent developments in quantum technology physics have shown tremendous progress in the storage,processing and transfer of quantum information using quantum bits (Qubits) [1][2][3].Quantum coherence which is a necessary requirement for realistic quantum communication system is extremely fragile and can be destroyed by interaction with the environment. Semiconductor quantum dots (QDs) embedded in micro-cavity have recently emerged as an attractive candidate for the implementation of quantum computing platforms [4][5][6][7][8]. Instead of the usual two-level real atoms, excitons in the QDs are considered as an alternative two level systems characterized by strong exciton-phonon interactions [9][10][11][12]. For practical implementation of quantum information processing based on QDs, it is important to minimize the influence of lattice vibrations which tends to destroy their coherence. Thus it is important to take into account exciton-phonon interactions in the study of quantum-dot cavity system. Experimental observation of vacuum Rabi Oscillations in atomic [13] as well as in solid state systems [14-16] provides evidence for strong coupling regime in micro cavity systems. Thus QDs embedded in semiconductor micro-cavity have emerged as an exciting platform to study cavity QED [17][18][19].Recently proposals have been put forward to use nano structured photonic nanocavities made of χ (2) nonlinear materials as prospectives devices for application in quantum information processing, quantum logic gates and all optical switches [20,21].One of the main aims of working with such systems is to have a scalable integrated quantum photonic technology with the probability to work at telecommunication wavelengths. In this paper, we seek to theoretically study the quantum oscillations in a coherently driven quantum dot-cavity system in the presence of a χ (2) nonlinear substrate and strong exciton-phonon interactions.

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