In this letter we consider Andreev tunneling between a normal metal and a one
dimensional Josephson junction array with finite-range Coulomb energy. The
I−V characteristics strongly deviate from the classical linear Andreev
current. We show that the non linear conductance possesses interesting scaling
behavior when the chain undergoes a T=0 superconductor-insulator transition of
Kosterlitz-Thouless-Berezinskii type. When the chain has quasi-long range
order, the low lying excitation are gapless and the I−V curves are power-law
(the linear relation is recovered when charging energy can be disregarded).
When the chain is in the insulating phase the Andreev current is blocked at a
threshold which is proportional to the inverse correlation length in the chain
(much lower than the Coulomb gap) and which vanishes at the transition point.Comment: 8 pages LATEX, 3 figures available upon reques
