Dissipation-assisted coherence formation in a spinor quantum gas

TL;DR

This paper demonstrates that spin-dependent dissipation in a spinor Bose-Einstein condensate can promote quantum coherence and induce spontaneous magnetization, revealing a novel way dissipation can enhance quantum order.

Contribution

It introduces the concept that dissipation, typically seen as destructive, can be harnessed to promote coherence and magnetization in a quantum gas, supported by experiments and simulations.

Findings

Spin-dependent dissipation induces quantum coherence.

Dissipation leads to spontaneous magnetic eigenstate formation.

Enhancement of magnetization despite non-ferromagnetic interactions.

Abstract

Dissipation affects all real-world physical systems and often induces energy or particle loss, limiting the efficiency of processes. Dissipation can also lead to the formation of dissipative structures or induce quantum decoherence. Quantum decoherence and dissipation are critical for quantum information processing. On the one hand, such effects can make achieving quantum computation much harder, but on the other hand, dissipation can promote quantum coherence and offer control over the system. It is the latter avenue -- how dissipation can be exploited to promote coherence in a quantum system -- that is explored in this work. We report the exploration of dissipation in a Bose-Einstein condensate (BEC) of spin-2 87Rb atoms. Through experiments and numerical simulations, we show that spin-dependent particle dissipation can give rise to quantum coherence and lead to the spontaneous formation of a magnetic eigenstate. Although the interactions between the atomic spins are not ferromagnetic, the spin-dependent dissipation enhances the synchronization of the relative phases among five magnetic sublevels, and this effects promotes magnetization.