Theoretical calculations of oneand two-hole spectral functions for the O nucleus are still failing to describe some of the important features observed experimentally. Of critical importance for the solution of these issues is to obtain an appropriate description of the interplay between hole-hole and particle-hole excitations. A formalism is reviewed here that allows the consistent treatment of...

Exciton-polaron formation in one-dimensional lattice models with shortor long-range carrier-phonon interaction is studied by quantum Monte Carlo simulations. Depending on the relative sign of electron and hole-phonon coupling, the exciton-polaron size increases or decreases with increasing interaction strength. Quantum phonon fluctuations determine the excitonpolaron size and yield translation-...

– The energy spectrum of the quantum Klein-Gordon (KG) lattice is computed numerically for some model parameters that are relevant for optical phonon spectra. A pairing of the phonon states is found when the nonlinearity is significant which agrees with other studies on different quantum lattice models [1,2]. It results from the anharmonic energy contribution the magnitude of which is quantifie...

Quantum transport in disordered systems has been studied for many years, yet many open problems remain. One focus of these investigations is the interference of inelastic electron scattering due to electron-phonon interaction and elastic electron scattering due to impurities, boundaries and defects. Electron-phonon interaction determines the electron energy loss rate and also manifests itself i...