Sensing decoherence by using edge state

Abstract

In the absence of decoherence the current of fermionic particles across a finite lattice connecting two reservoirs (leads) with different chemical potentials is known to be ballistic. It is also known that decoherence typically suppresses this ballistic current. However, if decoherence is weak, the change in the current may be undetectable. In this work we show that the effect of a weak decoherence can be amplified by orders of magnitude if the lattice has edge states.