Topological signatures in a weakly dissipative Kitaev chain of finite length

TL;DR

This paper develops a Lindblad master equation for a finite-length Kitaev chain coupled to thermal baths, revealing how topological properties influence quantum interference and steady-state transport phenomena.

Contribution

It introduces a global Lindblad framework for finite Kitaev chains with multiple baths, linking topological invariants to transport and interference effects.

Findings

Quantum interference arises from multi-site bath coupling.

Steady-state current follows a Landauer-Büttiker-like formula with an anomaly factor.

Topological properties affect the steady-state behavior and transport.

Abstract

We construct a global Lindblad master equation for a Kitaev quantum wire of finite length, weakly coupled to an arbitrary number of thermal baths, within the Born-Markov and secular approximations. We find that the coupling of an external bath to more than one lattice site generates quantum interference effects, arising from the possibility of fermions to tunnel through multiple paths. In the presence of two baths at different temperatures and/or chemical potentials, the steady-state particle current can be expressed through the Landauer-B\"uttiker formula, as in a ballistic transport setup, with the addition of an anomaly factor associated with the presence of the $p$-wave pairing in the Kitaev Hamiltonian. Such a factor is affected by the ground-state properties of the chain, being related to the finite-size equivalent of its Pfaffian topological invariant.