Metal–insulator-like transition in the energy spectrum of a one-dimensional proton (ionic) conductor

Abstract

We propose a modification of the well-known coherent potential approximation (CPA) for fermionic systems with short-range interactions. We calculate the spectra of a one-dimensional proton (ionic) conductor described by the fermionic lattice model within this approach. Depending on correlation values we observe either quasi-metallic or dielectric behaviour of the system at half-filling. Away from half filling, the system is always in the quasi-metallic state.