Single-particle spectrum for a model of fermions interacting with two-level local excitations on a lattice: A dynamical CPA approach
arXiv:cond-mat/0605050 · doi:10.1016/j.physleta.2006.04.058
Abstract
The problem of motion of a single electron interacting with a periodic lattice of two-level systems is investigated within a spinless fermion model. The Green's function is calculated in a single-site dynamical coherent potential approximation which is equivalent to DMFT. The picture of one-electron density of states is obtained for various values of the tunnel splitting and coupling between the electron and two-level system. The occurrence of a band splitting with increase of the coupling is demonstrated.
9 pages, 2 figures, Physics Letters A, accepted