Tunable coupling of a quantum phononic resonator to a transmon qubit with flip-chip architecture

TL;DR

This paper demonstrates a tunable, strong coupling between a surface acoustic wave resonator and a transmon qubit using a flip-chip technique, enabling advanced quantum acoustics research.

Contribution

It introduces a novel flip-chip method for achieving tunable, strong phonon-qubit coupling, expanding capabilities for hybrid quantum systems.

Findings

Coupling strength varies from 7.0 MHz to 20.6 MHz.

Observation of phonon-induced ac Stark shift.

Platform suitable for quantum acoustics exploration.

Abstract

A hybrid system with tunable coupling between phonons and qubits shows great potential for advancing quantum information processing. In this work, we demonstrate strong and tunable coupling between a surface acoustic wave (SAW) resonator and a transmon qubit based on galvanic-contact flip-chip technique. The coupling strength varies from $2\pi\times$7.0 MHz to -$2\pi\times$20.6 MHz, which is extracted from different vacuum Rabi oscillation frequencies. The phonon-induced ac Stark shift of the qubit at different coupling strengths is also shown. Our approach offers a good experimental platform for exploring quantum acoustics and hybrid systems.