Escrivà, AlbertMuñoz Mateo, AntonioGuilleumas, MontserratJuliá-Díaz, Bruno2020-01-222020-01-222019-12-092469-9926https://hdl.handle.net/2445/148458The 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.application/pdfeng(c) American Physical Society, 2019VòrtexsSuperfluïdesaCondensació de Bose-EinsteinVortex-motionSuperfluidityBose-Einstein condensationinfo:eu-repo/semantics/article6938792020-01-22info:eu-repo/semantics/openAccess