Enhanced suppresion of localization in a continuous Random-Dimer Model

TL;DR

This paper extends the Random Dimer model to a continuous setting, predicting infinitely many extended states due to multiple resonances, supported by numerical calculations.

Contribution

It introduces a continuous Kronig-Penney version of the Random Dimer model, revealing multiple resonances and extended states unlike the discrete case.

Findings

Infinite resonances lead to extended states

Numerical results support the presence of many extended states

Continuous model shows enhanced suppression of localization

Abstract

We consider a one-dimensional continuous (Kronig-Penney) extension of the (tight-binding) Random Dimer model of Dunlap et al. [Phys. Rev. Lett. 65, 88 (1990)]. We predict that the continuous model has infinitely many resonances (zeroes of the reflection coefficient) giving rise to extended states instead of the one resonance arising in the discrete version. We present exact, transfer-matrix numerical calculations supporting, both realizationwise and on the average, the conclusion that the model has a very large number of extended states.