Nanomechanical State Amplifier Based on Optical Inverted Pendulum

TL;DR

This paper introduces a nanomechanical state amplifier using optical levitation and potential switching, enabling precise control and squeezing of nanoparticle states for advanced nanotechnology and quantum applications.

Contribution

It presents a novel protocol for linear amplification and squeezing of nanomechanical states using a controlled potential switching method with experimental validation.

Findings

Achieved position amplification with gain |G| ≈ 2

Demonstrated >4 dB classical squeezing

Enhanced force sensing through velocity squeezing

Abstract

A contactless control of mean values and fluctuations of position and velocity of a nanoobject belongs among the key methods needed for ultra-precise nanotechnology and the upcoming quantum technology of macroscopic systems. An analysis of experimental implementations of such a control, including assessments of linearity and the effects of added noise, is required. Here, we present a protocol of linear amplification of mean values and fluctuations along an arbitrary phase space variable and squeezing along the complementary one, referred to as a nanomechanical state amplifier. It utilizes the experimental platform of a single optically levitating nanoparticle and the three-step protocol combines a controlled fast switching of the parabolic trapping potential to an inverted parabolic potential and back to the parabolic potential. The protocol can be sequentially repeated or extended to shape the nanomechanical state appropriately. Experimentally, we achieve amplification of position with a gain of $|G| \simeq 2$ and a classical squeezing coefficient above 4 dB in as short a timestep as one period of nanoparticle oscillations ($7.6\,\mu$s). Amplification in velocity, with the same parameters, squeezes the input noise and enhances force sensing.