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arXiv · 1607.02509

Anomalous conductances in an ultracold quantum wire

Márton Kanász-Nagy·Leonid Glazman·Tilman Esslinger·Eugene A. Demler
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Abstract

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.

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Márton Kanász-Nagy, Leonid Glazman, Tilman Esslinger, Eugene A. Demler. 2016-07-08. Anomalous conductances in an ultracold quantum wire. https://doi.org/10.1103/physrevlett.117.255302

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