A transmon qubit coupled to a circuit cavity is an extensively studied system, which has also been used to realize a wide variety of hybrid devices, such as with the cavity electromechanical systems. However, often the large power requirements for optomechanical systems render the c-QED setup incompatible. Motivated from this aspect, we investigate the relaxation of a transmon qubit after driving it to unconfined states with large power. We measure the resurgence time corresponding to the relaxation of qubit back to the ground state. After re-initializing the transmon to its ground state, we create single-photon states in the cavity by rapidly tuning the qubit frequency and swapping the single excitation to the cavity. These results pave the way for the integration of transmon qubit with optomechanical devices.
Dr Vibhor Singh is an assistant professor at the Indian Institute of Science Bangalore. Currently, his group is indulged in a variety of research activities, such as cavity-optomechanics in microwave domains, circuit-QED systems, superconducting qubit-based hybrid optomechanical systems. After obtaining his PhD from TIFR Mumbai, he was a postdoctoral researcher at the Delft University of Technology till 2015.