One-particle spectral densities and phase diagrams of one-dimensional proton conductors

TL;DR

This paper investigates the phase behavior and spectral properties of one-dimensional proton conductors using an extended boson lattice model and exact diagonalization, revealing various phases depending on interactions and external fields.

Contribution

It introduces a detailed model including short-range interactions, anharmonic potentials, and modulating fields, and maps out phase diagrams using spectral density analysis.

Findings

Multiple phases identified at zero temperature

Spectral density reveals phase transitions

Phase diagrams constructed based on interactions and fields

Abstract

The equilibrium states of one-dimensional proton conductors in the systems with hydrogen bonds are investigated. Our extended hard-core boson lattice model includes short-range interactions between hydrogen ions, their transfer along the hydrogen bonds with two-minima local anharmonic potential, as well as their inter-bond hopping, and the modulating field is taken into account. The exact diagonalization method for finite one-dimensional system with periodic boundary conditions is used. The existence of various phases of the system at $T = 0$, depending on the values of short-range interactions between particles and the modulating field strength, is established by analyzing the character of the obtained frequency dependence of one-particle spectral density; the phase diagrams are built.