Nonlocal electron–phonon coupling: influence on the nature of polarons

We present a variational approach to an extended Holstein model, comprising both local and nonlocal electron–phonon coupling. The approach is based on the minimization of a Bogoliubov bound to the free energy of the coupled electron-phonon system, and is implemented for a one-dimensional nearest-neighbor model, with Einstein phonons. The ambivalent character of nonlocal coupling, which both promotes and hinders transport, is clearly observed. A salient feature of our results is that the local and nonlocal couplings can compensate each other, leading to a supression of polaronic effects. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Hali tarjima qilinmagan