Squeezing and multimode entanglement of surface acoustic wave phonons

TL;DR

This paper demonstrates multimode entanglement and two-mode squeezing in a surface acoustic wave resonator with a SQUID, enabling potential applications in quantum information processing and continuous-variable quantum computing.

Contribution

The authors develop a multimode SAW resonator with integrated SQUID, achieving coupling among over 20 modes and demonstrating multimode entanglement and squeezing.

Findings

Achieved two-mode squeezing of SAW phonons.

Demonstrated four-mode multipartite entanglement.

Enabled potential for quantum computing applications.

Abstract

Exploiting multiple modes in a quantum acoustic device could enable applications in quantum information in a hardware-efficient setup, including quantum simulation in a synthetic dimension and continuous-variable quantum computing with cluster states.We develop a multimode surface acoustic wave (SAW) resonator with a superconducting quantum interference device (SQUID) integrated in one of the Bragg reflectors. The interaction with the SQUID-shunted mirror gives rise to coupling between the more than 20 accessible resonator modes. We exploit this coupling to demonstrate two-mode squeezing of SAW phonons, as well as four-mode multipartite entanglement. Our results open avenues for continuous-variable quantum computing in a compact hybrid quantum system.