Wave Transport in One-Dimensional Disordered Systems with Finite-Size Scatterers

TL;DR

This paper investigates wave transport in one-dimensional disordered systems with finite-size scatterers, revealing regimes of localization, transparency, and band gap formation, with analytical results supported by simulations.

Contribution

It introduces a detailed analysis of wave transport regimes in disordered chains with finite-size scatterers, including new insights into oscillatory behavior and band gap formation near specific phase conditions.

Findings

Exponential resistance growth in regime I

Near , system exhibits high transparency and less localization

Formation of a band gap at \u03b4 close to \u03c0 with increasing n

Abstract

We study the problem of wave transport in a one-dimensional disordered system, where the scatterers of the chain are $n$ barriers and wells with statistically independent intensities and with a spatial extension $\l_c$ which may contain an arbitrary number $\delta/2\pi$ of wavelengths, where $\delta = k l_c$. We analyze the average Landauer resistance and transmission coefficient of the chain as a function of $n$ and the phase parameter $\delta$. For weak scatterers, we find: i) a regime, to be called I, associated with an exponential behavior of the resistance with $n$, ii) a regime, to be called II, for $\delta$ in the vicinity of $\pi$, where the system is almost transparent and less localized, and iii) right in the middle of regime II, for $\delta$ very close to $\pi$, the formation of a band gap, which becomes ever more conspicuous as $n$ increases. In regime II, both the average Landauer resistance and the transmission coefficient show an oscillatory behavior with $n$ and $\delta$. These characteristics of the system are found analytically, some of them exactly and some others approximately. The agreement between theory and simulations is excellent, which suggests a strong motivation for the experimental study of these systems. We also present a qualitative discussion of the results.