Condensed Matter Seminar: Chaitanya Murthy

Almost Perfect Metals in One Dimension
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.
Reference: https://arxiv.org/abs/1909.04371