Asymmetry and nonlinearity of current-bias characteristics in superfluid-normal-state junctions of weakly interacting Bose gases

Uchino, Shun   

We uncover current-bias characteristics of superfluid-normal-state junctions with weakly interacting Bose gases. It is shown that in the presence of a chemical potential bias the characteristics can strongly be asymmetric for origin. The salient feature that is absent in the fermionic counterpart arises from a tunneling process associated with a condensate and a bosonic Andreev reflection process. It turns out that such processes are intrinsically nonlinear and therefore do not obey Ohm's law even at a low bias.