Fermionic approach to junctions of multiple quantum wires
Interacting quantum wires display exotic properties in junctions they form due to their one-dimensional Tomonaga-Luttinger liquid nature. These junctions have been theoretically analyzed by two complementary methods, namely bosonization and fermionic perturbation theory. In this talk, I will discuss a general fermionic approach to junctions of quantum wires, based on perturbation theory in interaction and renormalization of the scattering S-matrix, and carefully apply it to the case of infinite interacting leads whose effects were often ignored before. Our predictions on linear DC conductance and impurity entropy of the junction are in agreement with bosonization and early density matrix renormalization group results.