Quantum acoustic systems, which integrate surface or bulk phonons with superconducting qubits, offer a unique opportunity to investigate phononic interference and scattering processes in the quantum regime. In particular the interaction between a superconducting qubit and a phononic oscillator allows the qubit to sense the oscillator's excitation spectrum and underlying interference effects. Here we present measurements revealing Fano interference of a resonantly trapped piezoelectric surface acoustic wave (SAW) mode with a broad continuum of surface phonons in a system consisting of a SAW resonator coupled to a superconducting qubit. The experiments highlight the existence of additional weakly coupled mechanical modes and their influence on the qubit-phonon interaction and underscore the importance of phononic interference in quantum acoustic architectures that have been proposed for quantum information processing applications.
@article{arxiv.2302.01271,
title = {Quantum acoustic Fano interference of surface phonons},
author = {J. M. Kitzman and J. R. Lane and C. Undershute and N. R. Beysengulov and C. A. Mikolas and K. W. Murch and J. Pollanen},
journal= {arXiv preprint arXiv:2302.01271},
year = {2023}
}