Direct, Non-Destructive Imaging of Magnetization in a Spin-1 Bose Gas

TL;DR

This paper demonstrates a non-destructive imaging technique to spatially resolve magnetization in ultracold spin-1 gases, revealing persistent transverse magnetization in condensates suitable for high-resolution magnetometry.

Contribution

It introduces polarization-dependent phase-contrast imaging for direct, non-destructive magnetization measurement in spinor Bose gases, enabling detailed spatial and temporal analysis.

Findings

Transverse magnetization persists for condensate lifetime.

Magnetization response aligns with mean-field interaction models.

Noncondensed gas magnetization decoheres rapidly.

Abstract

Polarization-dependent phase-contrast imaging is used to spatially resolve the magnetization of an optically trapped ultracold gas. This probe is applied to Larmor precession of degenerate and nondegenerate spin-1 $^{87}$Rb gases. Transverse magnetization of the Bose-Einstein condensate persists for the condensate lifetime, with a spatial response to magnetic field inhomogeneities consistent with a mean-field model of interactions. Rotational symmetry implies that the Larmor frequency of a spinor condensate be density-independent, and thus suitable for precise magnetometry with high spatial resolution. In comparison, the magnetization of the noncondensed gas decoheres rapidly.