ANDREEV CONDUCTANCE OF A ONE-DIMENSIONAL INTERACTING ELECTRON-GAS COUPLED WITH A SUPERCONDUCTOR

Andreev reflection in a one-dimensional interacting electron gas coupl ed with a bulk superconductor is studied theoretically. In the case of weak interaction we calculate the renormalized Andreev-reflection amp litude using a poor man's renormalization group approach, taking accou nt of both the forward and backward scatterings due to the electron-el ectron interaction. The conductance as a function of temperature is ob tained for arbitrary strength of the barrier potential at the normal-s uperconductor interface. We show that the resulting temperature depend ence is stronger than that of single-barrier conductance in the one-di mensional interacting electron gas. It is also shown that any logarith mic temperature dependence does not appear in the Andreev conductance despite the presence of the backward scattering.