Spinor Boson Droplets Stabilized By Spin Fluctuations

TL;DR

This paper proposes that spin fluctuations in spin-1 Bose gases can stabilize self-trapped droplet states, offering a new platform for studying quantum droplets beyond dipolar gases and mixtures.

Contribution

It introduces spinor Bose gases as a novel candidate for droplet formation stabilized by spin fluctuations, expanding the understanding of quantum droplet systems.

Findings

Spin fluctuations stabilize dilute self-trapped states in spin-1 gases.

Polar droplet phase can be stabilized by spin fluctuations regardless of spin coupling type.

Quadratic Zeeman coupling allows tuning of droplet formation and density.

Abstract

Self-trapped droplets stabilized by quantum fluctuations have been experimentally realized in dipolar gases and binary Boson mixtures. We propose spinor Bose gases as another candidate for droplet formation in this work. For spin-1 gas, we find that spin fluctuations give a dilute but self-trapped state for two different order parameters where the mean-field picture predicts collapse. A polar droplet phase can be stabilized by spin fluctuations for both antiferromagnetic and ferromagnetic spin-dependent coupling. An antiferromagnetic droplet phase can be stabilized similarly with a negative quadratic Zeeman shift. Furthermore, the beyond mean-field energy of the system depends on the quadratic Zeeman coupling, which provides a mechanism to tune the droplet formation and its density. We discuss the parameters necessary for the experimental realization of such spinor droplets.