Acoustic radiation from a superconducting qubit: From spontaneous emission to Rabi oscillations

TL;DR

This paper investigates how a superconducting qubit interacts with acoustic resonators, demonstrating a transition from rapid decay to coherent phonon coupling, with implications for quantum memory and decoherence mitigation.

Contribution

It experimentally explores the crossover from spontaneous emission to Rabi oscillations in a qubit-acoustic resonator system by varying surface topography.

Findings

Demonstrated transition from fast decay to coherent coupling

Identified surface topography as a control parameter

Potential applications in quantum memories and loss studies

Abstract

Acoustic spontaneous emission into bulk dielectrics can be a strong source of decoherence in quantum devices, especially when a qubit is in the presence of piezoelectric materials. We study the dynamics of a qubit coupled to an acoustic resonator by a piezoelectric film. By varying the surface topography of the resonator from rough to polished to shaped, we explore the crossover from fast decay of an excited qubit to quantum-coherent coupling between the qubit and an isolated phonon mode. Our experimental approach may be used for precision measurements of crystalline vibrations, the design of quantum memories, and the study of electro-mechanical contributions to dielectric loss.