Mesoscopic Vortex-Meissner currents in ring ladders
  Recent experimental progress have revealed Meissner and Vortex phases in low-dimensional ultracold atoms systems. Atomtronic setups can realize ring ladders, while explicitly taking the finite size of the system into account. This enables the engineering of quantized chiral currents and phase slips in-between them. We find that the mesoscopic scale modifies the current. Full control of the lattice configuration reveals a reentrant behavior of Vortex and Meissner phases. Our approach allows a feasible diagnostic of the currents' configuration through time of flight measurements. 
Tobias Haug, Luigi Amico, Rainer Dumke, Leong-Chuan Kwek
cond-mat.quant-gas quant-ph