Quantum Non-Gaussian States of Superfluid Helium Vibrations

TL;DR

This paper proposes a method to generate and analyze quantum non-Gaussian states in superfluid helium vibrations, highlighting their potential for quantum technology and sensing applications.

Contribution

It introduces a photon counting detection scheme for creating quantum non-Gaussian phononic states in superfluid helium, with analysis of their robustness and applications.

Findings

High quantum non-Gaussian depth of phononic states

Confirmed single-phonon bunching capability

Enhanced force sensing and thermometry with more phonons

Abstract

Quantum non-Gaussian states of phononic systems coupled to light are essential for fundamental studies of single-phonon mechanics and direct applications in quantum technology. Although nonclassical mechanical states have already been demonstrated, more challenging quantum non-Gaussianity of such states remains limited. Using photon counting detection, we propose the quantum non-Gaussian generation of few-phonon states of low-temperature vibrating superfluid Helium. We predict the quantum non-Gaussian depth of such phononic states and investigate their robustness under relevant mechanical heating. As the quality of such phononic states is very high, we confirm a single-phonon bunching capability to further classify such states for future mechanical experiments. Moreover, we predict increasing capability for force sensing and thermometry for increasing heralded phonon numbers.