Meissner effect in a bosonic ladder

We investigate the effect of a magnetic field on a bosonic ladder. We show that such a system leads to the one-dimensional equivalent of a vortex lattice in a superconductor. We investigate the physical properties of the vortex phase, such as vortex density and vortex correlation functions, and show that magnetization has plateaus for some commensurate values of the magnetic field. The lowest plateau corresponds to a true Meissner to vortex transition at a critical field Hc1 that exists although the system has no long-range superconducting order. Implications for experimental realizations such as Josephson-junction arrays are discussed.