Ferroelectric quantum criticality

S. E. Rowley*, L. J. Spalek, R. P. Smith, M. P. M. Dean, M. Itoh, J. F. Scott, G. G. Lonzarich, S. S. Saxena

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

156 Citations (Scopus)

Abstract

Paramagnets on the border of ferromagnetism at low temperatures are more subtle and complex than anticipated by the conventional theory of quantum critical phenomena. Could quantum criticality theory be more relevant in the corresponding case of quantum paraelectrics on the border of ferroelectricity? To address this question we have investigated the temperature dependence of the dielectric function of the displacive quantum paraelectrics SrTiO3, oxygen-18 substituted SrTiO3 and KTaO3. In all of these materials on the border of ferroelectricity we observe non-classical T-2 temperature dependencies of the inverse dielectric function below 50 K, followed by anomalous upturns below a few kelvin extending into the millikelvin range. This non-classical behaviour can be understood quantitatively without adjustable parameters in terms of quantum criticality theory when extended to include the effects of long-range dipolar interactions and the coupling of the electric polarization field with acoustic phonons. The quantum critical regime in displacive ferroelectrics is thus strikingly different from that in the better-known ferromagnetic counterparts and offers unexpected prospects in the field of quantum phase transitions.

Original languageEnglish
Pages (from-to)367-372
Number of pages6
JournalNature Physics
Volume10
Issue number5
DOIs
Publication statusPublished - May 2014

Keywords

  • STRESS-INDUCED FERROELECTRICITY
  • PHASE-TRANSITIONS
  • LOW-TEMPERATURES
  • SRTIO3
  • SUPERCONDUCTIVITY
  • DEPENDENCE
  • BEHAVIOR
  • CRYSTAL
  • PHONON
  • KTAO3

Fingerprint

Dive into the research topics of 'Ferroelectric quantum criticality'. Together they form a unique fingerprint.

Cite this