Paraelectric-to-ferroelectric crossover and electron dynamics from time-dependent Hartree-Fock calculations

TL;DR

This paper investigates the electron and phonon dynamics during a paraelectric-to-ferroelectric crossover using time-dependent Hartree-Fock calculations, revealing a metastable spin Peierls state and analyzing phase transition behavior.

Contribution

It introduces a novel application of time-dependent Hartree-Fock to study electron-phonon dynamics and phase transitions, including spin degrees of freedom, in ferroelectric materials.

Findings

Identification of a thermally excited paraelectric-to-ferroelectric crossover.

Discovery of a metastable spin Peierls state.

Analysis of Landau expansion at quarter-filling.

Abstract

In recent years, researchers have discovered various excited states of electrons having an excited domain with a structural order different from the original one. We examine a dynamics of electron system and phonon system by using the time-dependent Hartree-Fock approximation. We examine time evolution with spin degree of freedom. We found a thermally excited paraelectric-to-ferroelectric crossover. The metastable state is spin pierls state. We also examine the Landau expansion of electron system at quarter-filled.