Polarization-Driven Charge Frustration and Emergent Phases in the One-Dimensional Extended Hubbard Model

TL;DR

This paper investigates how charge frustration caused by electronic polarization effects leads to the stabilization of unconventional insulating and ferroelectric phases in the one-dimensional extended Hubbard model, revealing new exotic quantum states.

Contribution

It demonstrates that charge frustration from charge-dipole interactions can induce novel insulating, ferroelectric, and charge-density-wave phases in a low-dimensional correlated system.

Findings

Identification of a charge-disordered insulating phase without long-range order

Discovery of a fragile ferroelectric phase driven by charge frustration

Observation of an emergent eight-site periodic charge-density-wave state

Abstract

Frustration is a key driver of exotic quantum phases, yet its role in charge dynamics remains largely unexplored. We show that charge frustration - induced by electronic polarization effects - stabilizes unconventional insulating states in the one-dimensional extended Hubbard model. Using exact diagonalization and density-matrix renormalization group, we uncover a charge-disordered phase that remains insulating despite lacking long-range order and possessing an effectively attractive on-site interaction - a behavior reminiscent of gapful spin liquids in frustrated spin systems. We also identify a fragile ferroelectric phase and a charge-density-wave state with emergent eight-site periodicity. These findings establish charge frustration, driven by charge-dipole interactions, as a robust mechanism for realizing exotic phases in low-dimensional correlated systems, with implications for organic conductors, transition-metal oxides, and ultracold polar molecules.