Figure 1: Optomechanics with a qubit.
From: Cavity optomechanics mediated by a quantum two-level system
(a) Illustration showing the idea for introducing a two-level system (qubit or artificial atom) into a cavity optomechanical setup. Inside the cavity (blue) there is a quantum two-level system (green), which is mechanically compliant (red). (b) Equivalent electrical circuit of the microwave design with the same colour codes as in a. The parameters in the equivalent circuit are C≃0.33 pF, L≃3.2 nH, Cg≃1.8 fF, CΣ≃4.9 fF, EJ=EJ1+EJ2≃10.5 GHz, EC≃5.3 GHz. The reflected pump microwave Vout is detected outside the cryostat. The Josephson junctions forming the qubit are marked by crossed boxes, and the mechanical resonator is coupled to the qubit island via a movable capacitance Cg(x). (c) Micrographs of the device showing the qubit and the mechanical resonator. The Josephson junctions are marked by arrows. Scale bar, 2 μm.
