Collisionless spin dynamics in a magnetic field gradient

TL;DR

This paper investigates the collisionless spin dynamics of a trapped Fermi gas in a magnetic field gradient, revealing periodic behavior, spin twisting, and interaction-induced beats through analytic and numerical methods.

Contribution

It introduces new analytic and numerical approaches to study spin dynamics in a trapped Fermi gas under magnetic field gradients, including effects of weak interactions.

Findings

System exhibits periodic spin evolution with twists and recurrences.

Weak interactions cause beat patterns in spin oscillations.

Analytic and numerical methods effectively describe the dynamics.

Abstract

We study the collisionless spin dynamics of a harmonically trapped Fermi gas in a magnetic field gradient. In the absence of interactions, the system evolution is periodic: the magnetization develops twists, which evolve into a longitudinal polarization. Recurrences follow. For weak interaction, the exchange interactions lead to beats in these oscillations. We present an array of analytic and numerical techniques for studying this physics.