Cyclic phase in F=2 spinor condensate: Long-range order, kinks, and roughening transition

TL;DR

This paper investigates how thermal fluctuations influence the long-range order, kink formation, and phase roughening in F=2 spinor Bose-Einstein condensates, revealing the emergence of a rough phase and analyzing kink properties.

Contribution

It introduces a combined approach using small-amplitude oscillations and sine-Gordon mapping to study thermal effects on F=2 condensates, highlighting the conditions for rough phase emergence.

Findings

Thermal fluctuations induce a rough phase in 1D and 2D systems.

Kinks are energetically favorable and characterized.

Thermal effects on F=1 condensate spin degrees are discussed.

Abstract

We study the effect of thermal fluctuations on homogeneous infinite Bose-Einstein condensate with spin F=2 in the cyclic state, when atoms occupy three hyperfine states with $m_{F}=0, \pm 2$. We use both the approach of small-amplitude oscillations and mapping of our model on the sine-Gordon model. We show that thermal fluctuations lead to the existence of the rough phase in one- and two-dimensional systems, when presence of kinks is favorable. The structure and energy of a single kink are found. We also discuss the effect of thermal fluctuations on spin degrees of freedom in F=1 condensate.