Dissipative cooling of spin chains by a bath of dipolar particles

TL;DR

This paper proposes a dissipative cooling method for spin chains of fermionic atoms in optical lattices, using dipolar interactions with a magnetic bath to efficiently produce low-energy entangled states within seconds.

Contribution

It introduces a novel dissipative approach leveraging dipolar interactions to rapidly cool and entangle spin chains, offering an alternative to traditional thermalization methods.

Findings

Dissipative cooling produces highly entangled low-energy spin states.

The process efficiently reaches the singlet ground state in a few seconds.

The method enables direct thermalization of spin degrees of freedom.

Abstract

We consider a spin chain of fermionic atoms in an optical lattice, interacting with each other by super-exchange interactions. We theoretically investigate the dissipative evolution of the spin chain when it is coupled by magnetic dipole-dipole interaction to a bath consisting of atoms with a strong magnetic moment. Dipolar interactions with the bath allow for a dynamical evolution of the collective spin of the spin chain. Starting from an uncorrelated thermal sample, we demonstrate that the dissipative cooling produces highly entangled low energy spin states of the chain in a timescale of a few seconds. In practice, the lowest energy singlet state driven by super-exchange interactions is efficiently produced. This dissipative approach is a promising alternative to cool spin-full atoms in spin-independent lattices. It provides direct thermalization of the spin degrees of freedom, while traditional approaches are plagued by the inherently long timescale associated to the necessary spatial redistribution of spins under the effect of super-exchange interactions.