Dynamical generation of spin squeezing in ultra-cold dipolar molecules

TL;DR

This paper investigates how long-range interactions in a two-dimensional ultracold fermionic dipolar molecular gas can generate robust spin squeezing, enabling advanced quantum sensing even under realistic conditions.

Contribution

It derives a long-range XXZ spin model for dipolar molecules and demonstrates robust spin squeezing and metrological protocols in this system.

Findings

Robust spin squeezing achieved at finite temperature.

Long-range interactions enable collective quantum dynamics.

Potential for enhanced quantum sensing applications.

Abstract

We study a bulk fermionic dipolar molecular gas in the quantum degenerate regime confined in a two-dimensional geometry. We consider two rotational states that encode a spin 1/2 degree of freedom. We derive a long-range interacting XXZ model describing the many-body spin dynamics of the molecules valid in the regime where motional degrees of freedom are frozen. Due to the spatially extended nature of the harmonic oscillator modes, the interactions in the spin model are very long-ranged and the system behaves close to the collective limit, resulting in robust dynamics and generation of entanglement in the form of spin squeezing even at finite temperature and in presence of dephasing and chemical reactions. We demonstrate how the internal state structure can be exploited to realise time-reversal and enhanced metrological sensing protocols.