engleski

Calculation of excited polaron states in the Holstein model

An exact diagonalization technique is developed to investigate the excited polaron states in the Holstein model for the infinite one-dimensional lattice. A new and comprehensive picture involving three excited (coherent) polaron bands below the phonon threshold is obtained. The fact that the Hamiltonian is invariant under the space inversion is used to show that the optical conductivity and single-electron absorption spectra are complementary. For the single-electron absorption the contributions of the coherent excited states of even parity are found to be important in the crossover regime. Furthermore, it is shown that in this regime the hybridization of two polaron states allows a straightforward description of the ground and first excited state. The connection between the excited bands and renormalized local phonon excitations of the strong coupling adiabatic theory is established.

polaron ; Holstein model ; excited states

Rad je kao predavanje prezentiran na skupu Annual APS March Meeting 2004, održanom od 22.-26. 03. 2004., Montreal, Kanada