Engineering spin waves in a high-spin ultracold Fermi gas

TL;DR

This paper explores the creation and control of complex spin-wave excitations in a high-spin ultracold Fermi gas, revealing novel tensorial behaviors and demonstrating precise manipulation of spin-currents.

Contribution

It introduces the study of tensorial spin-waves in an s=3/2 Fermi gas and demonstrates control over their properties through initial state tuning.

Findings

High-spin Fermi gas exhibits tensorial spin-wave modes.

Engineered initial states allow control of spin-current sign and magnitude.

Numerical and analytical models agree well with experimental data.

Abstract

We report on the detailed study of multi-component spin-waves in an s=3/2 Fermi gas where the high spin leads to novel tensorial degrees of freedom compared to s = 1/2 systems. The excitations of a spin-nematic state are investigated from the linear to the nonlinear regime, where the tensorial character is particularly pronounced. By tuning the initial state we engineer the tensorial spin-wave character, such that the magnitude and sign of the counterflow spin-currents are effectively controlled. A comparison of our data with numerical and analytical results shows excellent agreement.