Dynamics and thermodynamics in spinor quantum gases

TL;DR

This paper explores the dynamics and thermodynamics of spinor quantum gases, highlighting how external magnetic fields influence spin behavior and how these systems serve as models for Bose-Einstein condensation thermodynamics.

Contribution

It provides both theoretical and experimental insights into spin dynamics suppression and spatial variations, and investigates thermodynamic properties via condensate magnetization measurements.

Findings

Quadratic Zeeman effect suppresses spin dynamics.

Spatial variations observed in spin dynamics.

Condensate magnetization influenced by thermal bath interactions.

Abstract

We discuss magnetism in spinor quantum gases theoretically and experimentally with emphasis on temporal dynamics of the spinor order parameter in the presence of an external magnetic field. In a simple coupled Gross-Pitaevskii picture we observe a dramatic suppression of spin dynamics due to quadratic Zeeman ''dephasing''. In view of an inhomogeneous density profile of the trapped condensate we present evidence of spatial variations of spin dynamics. In addition we study spinor quantum gases as a model system for thermodynamics of Bose-Einstein condensation. As a particular example we present measurements on condensate magnetisation due to the interaction with a thermal bath.