Junction of several weakly interacting quantum wires: a renormalization   group study
  We study the conductance of three or more semi-infinite wires which meet at a junction. The electrons in the wires are taken to interact weakly with each other through a short-range density-density interaction, and they encounter a general scattering matrix at the junction. We derive the renormalization group equations satisfied by the S-matrix, and we identify its fixed points and their stabilities. The conductance between any pair of wires is then studied as a function of physical parameters such as temperature. We discuss the possibility of observing the effects of junctions in present day experiments, such as the four-terminal conductance of a quantum wire and crossed quantum wires. 
Siddhartha Lal (1), Sumathi Rao (2) and Diptiman Sen (1) ((1) IISc,   Bangalore, (2) Pennsylvania State University and HRI, ...