Quantum optical response of a hybrid optomechanical device embedded with a qubit

Abstract

We theoretically investigate the optical response in a hybrid quantum optomechanical system consisting of two optically coupled micro-cavities in which a two-level system (qubit) is coupled with a mechanical membrane. The qubit can either be a defect which interacts with the mechanical oscillator via the linear Jaynes–Cummings interaction or a superconducting charge qubit coupled with the mechanical mode via non-linear interaction. We find that coherent perfect transmission (CPT), coherent perfect synthesis (CPS) and optomechanically induced absorption (OMIA) can be generated by suitably adjusting the system parameters. We find that the qubit and its interaction with the mechanical oscillator emerges as a new handle to control these quantum optical properties. The presence of the qubit results in four points where CPT and CPS can be realized compared to the pure optomechanical case (i.e. in the absence of a qubit) where only three points are attained. This shows that the presence of the qubit gives us more flexibility in choosing the appropriate parameter regime where CPT and CPS can be attained and controlled. We also find that OMIA shows three distinct peaks both in the linear and non-linear cases. In the absence of the qubit, OMIA is converted to optomechanically induced transmission (OMIT). An increase in the qubit decay rate also shows a transition from OMIA to OMIT. Our study reveals that the optical response of the non-linear case is relatively rapid and more sensitive compared to the linear case to changes in the system parameters. This demonstrates the potential use of this hybrid system in designing a tunable all-optical switch and photon router, both of which form important elements of a quantum information network.