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arXiv · 0904.3972

Coherent potential approximation for spatially correlated disorder

Roland Zimmermann·Christoph Schindler
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Abstract

The coherent potential approximation (CPA) is extended to describe satisfactorily the motion of particles in a random potential which is spatially correlated and smoothly varying. In contrast to existing cluster-CPA methods, the present scheme preserves the simplicity of the conventional CPA in using a single self-energy function. Its accuracy is checked by a comparison with the exact moments of the Green's function, and with the spectral function from numerical simulations. The scheme is applied to excitonic absorption spectra in different spatial dimensions.

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Roland Zimmermann, Christoph Schindler. 2009-10-15. Coherent potential approximation for spatially correlated disorder. https://doi.org/10.1103/physrevb.80.144202

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