Persistent currents in spinor condensates

TL;DR

This study demonstrates the creation and stability analysis of persistent supercurrents in a two-component Bose gas with spinor degrees of freedom, revealing critical polarization thresholds and the importance of spin-magnitude for supercurrent stability.

Contribution

It provides experimental insights into supercurrent stability in spinor condensates, highlighting the role of spin polarization magnitude over orientation.

Findings

Supercurrents persist over two minutes at high spin-population imbalance.

Supercurrent stability depends on a critical spin polarization value.

Only the magnitude of the spin polarization vector affects supercurrent stability.

Abstract

We create and study persistent currents in a toroidal two-component Bose gas, consisting of $^{87}$Rb atoms in two different spin states. For a large spin-population imbalance we observe supercurrents persisting for over two minutes. However we find that the supercurrent is unstable for spin polarisation below a well defined critical value. We also investigate the role of phase coherence between the two spin components and show that only the magnitude of the spin-polarisation vector, rather than its orientation in spin space, is relevant for supercurrent stability.