Anomalous conductances in an ultracold quantum wire
  We analyze the recently measured anomalous transport properties of an ultracold gas through a ballistic constriction [S. Krinner et al., PNAS 201601812 (2016)]. The quantized conductance observed at weak interactions increases several-fold as the gas is made strongly interacting, which cannot be explained by the Landauer theory of single-channel transport. We show that this phenomenon is due to the multichannel Andreev reflections at the edges of the constriction, where the interaction and confinement result in a superconducting state. Andreev processes convert atoms of otherwise reflecting channels into the condensate propagating through the constriction, leading to a significant excess conductance. Furthermore, we find the spin conductance being suppressed by superconductivity; the agreement with experiment provides an additional support for our model. 
M\'arton Kan\'asz-Nagy, Leonid Glazman, Tilman Esslinger, and Eugene   A. Demler
cond-mat.quant-gas cond-mat.mes-hall cond-mat.supr-con physics.atom-ph