Physics (Internal)

Topological Transitions in Dissipative Quantum Transport

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:
We investigate quantum transport in a family of one-dimensional
models where a particle can decay whenever it visits sites on one of two sublattices. The corresponding non-Hermitian tight-binding problem
exhibits distinct topological phases, characterized by a winding number defined in terms of the Bloch eigenstates in the Brillouin zone. We find that the mean displacement of a particle initially localized on one of the
nondecaying sites can be expressed in terms of the winding number, and
is therefore quantized as an integer, changing from zero to one at the
critical point. This distinctive and robust feature can be used as an
experimental test for quantum behavior in multilevel systems such as
Josephson arrays, and holds additional implications for photon and
nuclear spin pumping.