In a magnetoelectric-antiferromagnetic LiCoPO4 single crystal, we established a single-domain state by illuminating the crystal by light while cooling it through the Néel temperature. The experimental results and symmetry analysis indicate that the thermal gradient and resulting heat flow are responsible for this novel effect. Such a domain selection is a consequence of the magnetoelectric anisotropy in diffusive transport [Phys. Rev. Lett. 94, 016601 (2005)], i.e. nonreciprocal propagation of thermally-activated quasi-particles in different antiferromagnetic domains. The microscopic mechanism behind the observed effect and the dynamics of the process are however not clear at the moment, calling for future theoretical modeling.
The seminar will be chaired by Hynek Němec, Department of Dielectrics.