Possible nonlinear excitations in quasi-one-dimensional halogen-bridged binuclear metal complexes

Abstract

We investigate possible localized intragap states in quasi-one-dimensional halogen-bridged binuclear metal (MMX) complexes. Within a coupled electron-phonon model, soliton and polaron excitations in the two distinct ground states of MMX chains are numerically calculated and compared. Their effective masses are predicted for typical MMX compounds. Making a continuum-model analysis as well, we further reveal their scaling properties with particular emphasis on the analogy between MMX chains and trans-polyacetylene.