Theory of quantum paraelectrics and the metaelectric transition

TL;DR

This paper develops a microscopic model for quantum paraelectric-ferroelectric transitions, highlighting how coupled phonon fluctuations can induce a first-order transition, textured phases, and unique thermodynamic behaviors.

Contribution

It introduces a novel microscopic framework that explains fluctuation-driven phenomena and phase transition characteristics in quantum paraelectrics.

Findings

Fluctuations can turn a continuous transition into a first-order one.

Emergence of textured phases preempting the transition.

Inverse susceptibility shows T^2 quantum critical behavior.

Abstract

We present a microscopic model of the quantum paraelectric-ferroelectric phase transition with a focus on the influence of coupled fluctuating phonon modes. These may drive the continuous phase transition first order through a metaelectric transition and furthermore stimulate the emergence of a textured phase that preempts the transition. We discuss two further consequences of fluctuations, firstly for the heat capacity, and secondly we show that the inverse paraelectric susceptibility displays T^2 quantum critical behavior, and can also adopt a characteristic minimum with temperature. Finally, we discuss the observable consequences of our results.