Piezoelectric loss in superconducting quantum circuits: Part 1*

In recent studies, it has been shown that strong coupling between a superconducting qubit and phonons can be achieved. [1,2] These results imply that any unintended electro mechanical coupling in the system could lead to loss in superconducting circuit systems. In my talk, I will present a highly sensitive technique for measuring electromechanical coupling in a material at cryogenic temperatures and in the GHz regime. The measurement is based on RF driving of phonons through electromechanical coupling and optical readout through Brillouin scattering. I will present measurements done on an inversion symmetric material, the progress on relevant materials for superconducting circuits, and discuss its implications for qubit coherence times.
[1] Y. Chu, et al. Science (2018)
[2] K. Satzinger, et al. Science (2018)