Quantum fluctuation and geometrical frustration effects on electric polarization

TL;DR

This paper explores how quantum fluctuations and geometrical frustration in layered iron oxides can induce ferroelectricity through electronic charge order, challenging traditional views on quantum effects in ferroelectric materials.

Contribution

It introduces a theoretical model showing that quantum fluctuations and geometrical frustration together can generate electric polarization without inversion symmetry.

Findings

Quantum fluctuations promote electric polarization in layered iron oxides.

Geometrical frustration enhances the stability of ferroelectric charge order.

Results contrast with conventional quantum fluctuation mechanisms in ferroelectricity.

Abstract

We examine theoretically a possibility of ferroelectricity caused by electronic charge order without inversion symmetry, motivated by layered iron oxides. Quantum electronic models in a paired-triangular lattice are analyzed by utilizing the variational Monte Carlo simulation. Our calculation demonstrates that combined effects of electron transfer between the layers, corresponding to quantum fluctuation between the potential minima, and geometrical frustration promote appearance of an electric polarization. Present results are in contrast to the conventional manner of quantum fluctuation in ferroelectricity.