Hosted by Erich Mueller

Title: Almost Perfect Metals in One Dimension

Abstract: I will show that a one-dimensional quantum wire with as few as 2 channels of interacting fermions can host metallic states of matter (Luttinger liquids) that are stable against all perturbations up to q^th-order in fermion creation/annihilation operators, for any fixed finite q. Thus, in these phases, weak disorder does not lead to localization, a weak periodic potential fails to open a gap, and contact with a superconductor also fails to open a gap. The leading relevant perturbations are complicated operators that are expected to modify the physics only at very low energies, below accessible temperatures. The stability of these non-Fermi liquid fixed points is due to strong interactions between the channels, which can (but need not) be chosen to be purely repulsive. Our results might enable elementary physical realizations of these phases.