Shot-to-shot noise cancellation for parametric oscillators

TL;DR

The paper introduces a spin-echo inspired decoupling protocol to cancel shot-to-shot force noise in parametric oscillator squeezing experiments, demonstrated with an optically levitated nanoparticle.

Contribution

It presents a novel shot-to-shot noise cancellation technique based on oscillator-echo, improving quantum squeezing experiments by mitigating slow varying forces.

Findings

Shot-to-shot noise suppressed to the measurement-backaction limit.

Protocol effectively cancels slowly varying stray field forces.

Demonstrated with an optically levitated nanoparticle.

Abstract

Powerful approaches to squeeze the motional state of a harmonic oscillator rely on the stepwise modulation of its resonance frequency. Such protocols can be limited by forces that vary slowly between experimental runs but are constant during a single experimental shot. Such shot-to-shot noise gives rise to a spread in experimental outcomes that masks the uncertainty intrinsic to quantum theory. Taking inspiration from spin-echo protocols, we propose a decoupling technique that, under ideal conditions, perfectly cancels shot-to-shot force noise in squeezing experiments based on parametric modulation. We implement the protocol using an optically levitated nanoparticle, where shot-to-shot force noise arises from slowly varying stray fields acting on the charge carried by the particle. Using our oscillator-echo protocol, we demonstrate shot-to-shot noise suppression to the measurement-backaction limit.