### Session Y26: General Theory / Computational Physics I

8:00 AM–11:00 AM, Friday, March 2, 2012
Room: 257B

Chair: Amy Bug, Swarthmore College

Abstract ID: BAPS.2012.MAR.Y26.6

### Abstract: Y26.00006 : Exponential tails near the band edges of a one-dimensional disordered exciton system in the Coherent Potential Approximation

9:00 AM–9:12 AM

Preview Abstract MathJax On | Off   Abstract

#### Authors:

Abdelkrim Boukahil
(Physics Department, University of Wisconsin-Whitewater)

Nouredine Zettili
(Deprtment of Physical and Earth Sciences, Jacksonville State University, 700 Pelham Road North, Jacksonville, AL 36265, USA)

David Huber
We report the results of studies of the tails near the band edges of a one-dimensional Frenkel exciton system in the Coherent Potential Approximation (CPA). A Gaussian distribution of the transition frequencies with rms width $\sigma$ (0.1 $\le \sigma \le$ 2.0) is used. We found that the tails obey two different exponential power laws depending on the value of $\sigma$. In the weak disorder limit 0.1 $\le \sigma <$ 0.5, the tails of the absorption line shape and the density of states behave like $exp(-k|E|^{3/2} / \sigma^2)$, and in the strong disorder limit,\textit{0.5 $< \sigma \le$ 2.0}, the tails behave like $exp(-|E|^2 / \sigma^2)$. In the weak disorder limit, our CPA results are in excellent agreement with previous investigations.