Correlation - Function Analysis of Coupled Electron - Phonon Systems: Signatures of Polaron Tunneling

Intrinsic 'local textures' are becoming a leitmotiv of complex electronic materials, including high-Tc superconductors. Here we discuss signatures of nonlinear dynamics in the context of small polarons through various correlation functions which measure correlated structural and optical properties of a system. It is shown that energy-resolved correlation functions can be used to probe length and time scales in a unique fashion. These methods are applied to a polaron-tunneling problem which not only serves as a prototype for nonlinear and nonadiabatic behaviour in the presence of coupled electronic and lattice degrees of freedom, but may also be relevant to discraibing aspects of local electronic and structural dynamics in high-Tc superconducting materials. (author)