Strong indirect coupling between graphene-based mechanical resonators via a phonon cavity

TL;DR

This paper demonstrates strong indirect coupling between separated graphene-based mechanical resonators mediated by a phonon cavity, enabling long-distance mechanical interactions for quantum and classical information processing.

Contribution

It reports the first experimental observation of tunable strong indirect coupling between distant mechanical resonators via a phonon cavity in a graphene system.

Findings

Strong indirect coupling observed between separated resonators

Coupling mediated by a far-off-resonant phonon cavity

Tunable coupling achieved by controlling phonon cavity frequency

Abstract

Mechanical resonators are promising systems for storing and manipulating information. To transfer information between mechanical modes, either direct coupling or an interface between these modes is needed. In previous works, strong coupling between different modes in a single mechanical resonator and direct interaction between neighboring mechanical resonators have been demonstrated. However, coupling between distant mechanical resonators, which is a crucial request for long-distance classical and quantum information processing using mechanical devices, remains an experimental challenge. Here, we report the experimental observation of strong indirect coupling between separated mechanical resonators in a graphene-based electromechanical system. The coupling is mediated by a far-off-resonant phonon cavity through virtual excitations via a Raman-like process. By controlling the resonant frequency of the phonon cavity, the indirect coupling can be tuned in a wide range. Our results may lead to the development of gate-controlled all-mechanical devices and open up the possibility of long-distance quantum mechanical experiments.