arXiv:1908.01353 · Physical Review A

Tunneling vortex dynamics in linearly coupled Bose-Hubbard rings

Albert Escrivà, Antonio Muñoz Mateo, M. Guilleumas, Bruno Juliá-Díaz

Published Dec 9, 2019• 12 citations

Abstract

The quantum dynamics of population-balanced fractional vortices and population-imbalanced vortices in an effective two-state bosonic system, made of two coupled discrete circuits with few sites, is addressed within the Bose-Hubbard model. We show that, for low on-site interaction, the tunneling of quantized vortices between the rings performs a coherent, oscillating dynamics connecting current states with chiral symmetry. The vortex-flux transfer dually follows the usual sinusoidal particle current of the Josephson effect, in good agreement with a mean-field approximation. Within such a regime, the switch of persistent currents in the rings resembles flux-qubit features and is feasible for experimental realization. On the contrary, strong interatomic interactions suppress the chiral current and lead the system into fragmented condensation.

DOI: 10.1103/physreva.100.063621

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