# Fractionalization of long-range ordered states in a Falicov-Kimball model

## TL;DR

This paper investigates a Falicov-Kimball model using dynamical mean-field theory, revealing fractionalization of particles into charge and spin components with distinct properties in different temperature and interaction regimes.

## Contribution

It demonstrates the fractionalization phenomenon in a long-range ordered phase within the Falicov-Kimball model, highlighting the universal scaling of charge and spin excitations.

## Key findings

- Charge and spin fractionalization occurs in both high- and low-temperature phases.
- Single-particle spectra are always gapped in the low-temperature phase.
- Charge and spin excitations are gapless in the strong interaction regime.

## Abstract

A Falicov-Kimball model which thermodynamically reduces the local Coulomb interaction of particles to attraction or repulsion is studied within the dynamical mean-field theory. In the strong interaction regime a fractionalization of particles into charge and spin objects, the physical properties of which are different from the whole particles, is observed in both high- and low-temperature phases. At high temperature and strong interaction the single-particle density of states opens an excitation gap, but the charge compressibility and the spin susceptibility exhibit the features of gapless excitations. The low-temperature phase has a long-range order, and the single-particle spectra are always gapped, while the charge and spin excitations are gapless in the strong interaction regime. In the fractionalized long-range ordered phase both the charge compressibility and the spin susceptibility are universal scaling functions of temperature.