Universal transport signatures of Majorana fermions in superconductor-Luttinger liquid junctions

One of the most promising proposals for engineering Majorana fermions employs a spin-orbit-coupled nanowire proximate to an s-wave superconductor. When only part of the wire's length contacts to the superconductor, the remaining conducting portion serves as a natural lead that can be used to probe these Majorana modes via tunneling. The enhanced role of interactions in 1D dictates that this configuration should be viewed as a superconductor-Luttinger liquid junction. We demonstrate that low-energy transport in such junctions is \emph{universal}, and governed by fixed points describing either perfect normal reflection or perfect Andreev reflection. In addition to capturing (in some instances) the familiar Majorana-mediated zero-bias anomaly in a new framework, we show that interactions yield dramatic consequences in certain regimes. Implications for conductance and local density of states measurements will be discussed.