Single and two-mode mechanical squeezing of an optically levitated nanodiamond via dressed-state coherence

TL;DR

This paper demonstrates a method to generate single and two-mode mechanical squeezed states in an optically levitated nanodiamond using dressed-state coherence, achievable at room temperature and without cavities.

Contribution

It introduces a cavity-free, deterministic approach for creating macroscopic squeezed states via dressed-state coherence in a levitated nanodiamond.

Findings

Quantum squeezing achievable at room temperature in ultrahigh vacuum.

Cryogenic temperatures needed for squeezing at moderate vacuum.

Two-mode squeezing demonstrated with coupled mechanical modes.

Abstract

Nonclassical states of macroscopic objects are promising for ultrasensitive metrology as well as testing quantum mechanics. In this work, we investigate dissipative mechanical quantum state engineering in an optically levitated nanodiamond. First, we study single-mode mechanical squeezed states by magnetically coupling the mechanical motion to a dressed three-level system provided by a Nitrogen-vacancy center in the nanoparticle. Quantum coherence between the dressed levels is created via microwave fields to induce a two-phonon transition, which results in mechanical squeezing. Remarkably, we find that in ultrahigh vacuum quantum squeezing is achievable at room temperature with feedback cooling. For moderate vacuum, quantum squeezing is possible with cryogenic temperature. Second, we present a setup for two mechanical modes coupled to the dressed three levels, which results in two-mode squeezing analogous to the mechanism of the single-mode case. In contrast to previous works, our study provides a deterministic method for engineering macroscopic squeezed states without the requirement for a cavity.