Electronic transport in a randomly amplifying and absorbing chain

TL;DR

This paper investigates how randomness and non-hermiticity in a one-dimensional system affect electronic transport, revealing that disordered imaginary potentials can alter decay rates of transmittance compared to traditional Anderson localization.

Contribution

It introduces a model with random imaginary potentials in a non-hermitian Hamiltonian, analyzing their impact on localization and transmittance decay.

Findings

Transmittance decays exponentially with distance.

Disordered imaginary potentials can slow down transmittance decay.

Contrast with Anderson localization where real disorder causes localization.

Abstract

We study localization properties of a one-dimensional disordered system characterized by a random non-hermitean hamiltonian where both the randomness and the non-hermiticity arises in the local site-potential; its real part being ordered (fixed), and a random imaginary part implying the presence of either a random absorption or amplification at each site. The transmittance (forward scattering) decays exponentially in either case. In contrast to the disorder in the real part of the potential (Anderson localization), the transmittance with the disordered imaginary part may decay slower than that in the case of ordered imaginary part.