Fluctuations and Criticality in Quantum Paraelectrics

TL;DR

This paper models the temperature-dependent dielectric susceptibility of quantum paraelectrics like SrTiO3, revealing critical fluctuations and proposing experimental methods to realize quantum critical states.

Contribution

It introduces a self-consistent mean fluctuation field approach to analyze quantum paraelectrics and identifies conditions for quantum criticality through pressure or doping.

Findings

Qualitative agreement with experimental data on SrTiO3

Identification of a gaped quantum paraelectric state

Proposal for realizing quantum criticality experimentally

Abstract

The temperature dependence of static dielectric susceptibility of a system with strongly coupled fluctuating dipoles is calculated within a self consistent mean fluctuation field approximation. Results are qualitatively in good agreement with, a quantum paraelectric, SrTiO$_3$ in the low temperature regime. We identify this system as a {\it gaped quantum paraelectric} and suggest a possible experimental realization of a {\it quantum critical paraelectric} through the application of hydrostatic pressure or doping by impurity.