Melting of Polarization Vortices Crystals and Chiral Phase Transitions in Oxide Superlattices

Abstract

We study the equilibrium arrangements of polarization vortices in (PbTiO${}_3$)${}_n$/(SrTiO${}_3$)${}_n$ superlattices by means of second-principles simulations. We find that, at low temperatures, polarization vortices organize in a regular arrangement in which clockwise and counter-clockwise vortices alternate positions, leading to a crystal-like structure with well defined handedness. This chiral crystal melts at a critical temperature $T_{\mathrm{M}}$ into a chiral liquid, where long-range order is lost but handedness is preserved. At even higher temperatures, $T_{\mathrm{C}}$, a second phase transition occurs, at which the chiral liquid of polarization vortices loses its handedness. Both phase transitions can be readily identified by the adequate choices of order parameters.

7 pages, 4 figures

References in corpus (1)

• Berezinskii-Kosterlitz-Thouless Phase in Two-dimensional Ferroelectrics

Cited by in corpus (4)

• Assessing the nature of nanoscale ferroelectric domain walls in lead titanate multilayers
• Topological phase transitions in perovskite superlattices driven by temperature, electric field, and doping
• Kittel law and domain formation mechanism in PbTiO${}_3$/SrTiO${}_3$ superlattices
• Liquid-crystal-like dynamic transition in ferroelectric/dielectric superlattices