Summary of Previous Research Accomplishments 

A. We report a quantum switch that can control the heat transport between two nominally identical incoherent heat reservoirs. The heat switch is a X-mon qubit whose level spacing is tunable by an externally applied magnetic field. Each heat reservoir consists of a quarter-wavelength coplanar waveguide resonator, which is capacitively coupled to the qubit at one end and terminated to the ground via a copper strip at the other end. The copper strip is DC connected to two aluminum electrodes through aluminum oxide tunnel barriers, forming a superconductor-insulator-normal metal-insulator-superconductor (SINIS) tunneling device. The copper strip plays the role of heater in one reservoir and the SINIS in the other reservoir serves as a thermometer. We observed tunable photonic heat transport through this reservoir-qubit-reservoir circuit and noted that the interplay between the qubit-resonator coupling g and the resonator-reservoir coupling g can lead to qualitatively dissimilar switching behaviors. 

B. We devised a powerful approach in calibrating Fabry-Perot-based nanomechanical resonators using the fundamental wave interference phenomenon. Using a green laser (wavelength = 532nm) as the light source, we resolved subnanometer displacement amplitudes both in the frequency and spatial domain for circular and elliptical optoelectromechanical resonators and mapped the profile of drumhead oscillations. We also reported the observation of mechanical motion at off-resonance frequencies in the nanoscale regime. This innovative way of using spatial resolved measurement allows for the determination of the behavior of the modal weights in between resonances. These modal weights not only describe the transition from one resonance mode to the other but hints on modes that are favored by the system. The optoelectromechanical oscillators can serve as a quantum transducer that couples to both qubit-information carrying microwave photons and quantum-communication optical photons. The knowledge about oscillation displacement as well as the drumhead profile are crucial for its application in optical quantum information teleportation of superconducting qubit states.