ANOMALOUS DENSITY-OF-STATES OF A LUTTINGER LIQUID IN CONTACT WITH A SUPERCONDUCTOR

We study the frequency and space dependence of the local tunneling den sity of states (DOS) of a Luttinger liquid (LL) connected to a superco nductor. This coupling strongly modifies the single-particle propertie s of the LL. It significantly enhances the DOS near the Fermi level, w hereas this quantity vanishes as a power law for an isolated LL. The e nhancement is due to the interplay between electron-electron interacti ons and multiple backscattering processes of low-energy electrons at t he interface between the LL and the superconductor. This anomalous beh avior extends over large distances from the interface and may be detec ted by coupling normal probes to the system.