First Order Phase Transition in Quantum Paraelectrics

TL;DR

This paper analyzes pressure-induced phase transitions in quantum paraelectrics, showing they are typically first order near the quantum critical point, supported by microscopic theory and recent experiments.

Contribution

It demonstrates that quantum paraelectrics undergo first order phase transitions near the critical point, based on a microscopic theory and Landau analysis, extending understanding of their transition nature.

Findings

Transition temperature scales as (1 - p/p_c)^{1/2} near criticality

Most quantum paraelectrics exhibit first order transitions at the quantum critical point

Experimental evidence supports the theoretical prediction

Abstract

We discuss the nature of pressure induced phase transitions in standard Quantum Paraelectrics near quantum critical point. From a microscopic theory we first show that near the critical point the transition temperature $T_c(p)$ varies as $ (1-p/p_c)^\xi$ with $\xi={1/2}$. Within the Landau scheme, it is shown that for $\xi \leq 1$, a condition satisfied by most quantum paraelectrics the transition is inevitably first order in nature. The present analysis is valid for non-polar impurity induced transitions in these materials and is supported by some recent experiment.