Physics

News and events

18 June 2019

Research seminar: Z2 vortex crystals in triangular antiferromagnets with strong spin orbit coupling

Presented By Ioannis Rousochatzakis (Loughborough)
  • 12:00-13:00
  • DAV.1.106 Sir David Davies

About this event

Abstract

The triangular-lattice Heisenberg antiferromagnet is known to carry topological Z2 vortex excitations which form a gas at finite temperatures.  In this seminar, we will discuss how the spin-orbit interaction can condense these vortices into a triangular Z2 vortex crystal at zero temperature.  This is an example of a commensurate-incommensurate nucleation transition, analogous to the spontaneous formation of magnetic domains, Abrikosov vortices in type-II syperconductors, blue phases in cholesteric liquid crystals, and skyrmions in chiral helimagnets.  As the mechanism relies on the interplay of geometric frustration and spin-orbital anisotropies, such vortex mesophases can materialize as a ground-state property in spin-orbit coupled correlated systems with hexagonal symmetry.  I will also discuss how the vortices can be most saliently identified in experiment.