arXiv:1511.02320 · Physical Review A

Criticality and spin squeezing in the rotational dynamics of a Bose-Einstein condensate on a ring lattice

M. Kolář, Tomáš Opatrný, Kunal K. Das

Published Oct 28, 2015• 17 citations

Abstract

We examine the dynamics of circulating modes of a Bose-Einstein condensate confined in a toroidal lattice. Nonlinearity due to interactions leads to criticality that separates oscillatory and self-trapped phases among counterpropagating modes which however share the same physical space. In the mean-field limit, the criticality is found to substantially enhance sensitivity to rotation of the system. Analysis of the quantum dynamics reveals the fluctuations near criticality are significant, which we explain using spin-squeezing formalism visualized on a Bloch sphere. We utilize the squeezing to propose a Ramsey interferometric scheme that suppresses fluctuation in the relevant quadrature sensitive to rotation.

DOI: 10.1103/physreva.92.043630

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