Proposal for quantum many-body simulation and torsional matter-wave interferometry with a levitated nanodiamond

TL;DR

This paper proposes a novel method to strongly couple NV center spins with torsional vibrations of a levitated nanodiamond in a uniform magnetic field, enabling quantum simulations and matter-wave interferometry.

Contribution

It introduces a new spin-torsional coupling mechanism in a uniform magnetic field, allowing multiple spins to interact simultaneously and enabling quantum simulation of the LMG model.

Findings

Strong spin-torsional coupling achieved in uniform magnetic field.

Observation of quantum phase transition in the LMG model.

Proposal for torsional matter-wave interferometry.

Abstract

Hybrid spin-mechanical systems have great potentials in sensing, macroscopic quantum mechanics, and quantum information science. In order to induce strong coupling between an electron spin and the center-of-mass motion of a mechanical oscillator, a large magnetic gradient is usually required, which is difficult to achieve. Here we show that strong coupling between the electron spin of a nitrogen-vacancy (NV) center and the torsional vibration of an optically levitated nanodiamond can be achieved in a uniform magnetic field. Thanks to the uniform magnetic field, multiple spins can strongly couple to the torsional vibration at the same time. We propose to utilize this new coupling mechanism to realize the Lipkin-Meshkov-Glick (LMG) model by an ensemble of NV centers in a levitated nanodiamond. The quantum phase transition in the LMG model and finite number effects can be observed with this system. We also propose to generate torsional superposition states and realize torsional matter-wave interferometry with spin-torsional coupling.