Mesoscopic superfluid-to-superconductor transition
Phys. Rev. A 113, 032221 – Published 30 March, 2026
DOI: https://doi.org/10.1103/tssc-m89q
Abstract
Spectrum tomography for the energy () of a ring-shaped Bose-Hubbard circuit is illustrated. There is an interparticle interaction that controls superfluidity (SF) and the transition to the Mott insulator (MI) regime. The circuit is coupled to an electromagnetic cavity mode of frequency , and the coupling is characterized by a generalized fine-structure constant that controls the emergence of superconductivity (SC). The diagram features SF and SC regions, a vast region of fragmented possibly chaotic states, and an MI regime for large . The mesoscopic version of the Meissner effect and the Anderson-Higgs mechanism are discussed.