A strongly-coupled $\Lambda$-type micromechanical system

TL;DR

This paper demonstrates a three-mode strongly-coupled micromechanical system using high-Q resonators, enabling phenomena like dark states and coherent population trapping, advancing phononic circuit architectures.

Contribution

It introduces a novel $ ext{Lambda}$-type three-level micromechanical system with strong dynamic coupling and quantum-like phenomena, extending previous two-level systems.

Findings

Realized strong two-mode coupling via dielectric force.

Observed a mechanical 'dark' state and coherent population trapping.

Provides new design principles for phononic circuits.

Abstract

We study a classical $\Lambda$-type three-level system based on three high-$Q$ micromechanical beam resonators embedded in a gradient electric field. By modulating the strength of the field at the difference frequency between adjacent beam modes, we realize strong dynamic two-mode coupling, via the dielectric force. Driving adjacent pairs simultaneously, we observe the formation of a purely mechanical 'dark' state and an all-phononic analog of coherent population trapping --- signatures of strong three-mode coupling. The $\Lambda$-type micromechanical system is a natural extention of previously demonstrated 'two-level' micromechanical systems and offers new perspectives on the architecture of all-phononic micromechanical circuits and arrays.