Theory of colossal magnetoelectric response near spin-flop transition in Ni3TeO6

The manipulation of magnetic ordering with applied electric fields is of pressing interest for new spintronic and information storage applications. Recently, such magnetoelectric control was realized in multiferroics [1]. However, their magnetoelectric switching is often accompanied by significant hysteresis, resulting from a large barrier, separating different ferroic states. Hysteresis prevents robust switching, unless the applied field overcomes a certain value (coercive field). I will discuss the role of a switching barrier on magnetoelectric control, in particular, in a collinear antiferromagnetic and pyroelectric Ni3TeO6 [2,3]. The barrier between two magnetic states in the vicinity of a spin–flop transition is almost flat, and thus small changes in external electric/magnetic fields allow to switch the ferroic state through an intermediate state in a continuous manner, resulting in a colossal magnetoelectric response. This colossal magnetoelectric effect resembles the large piezoelectric effect at the morphotropic phase boundary in ferroelectrics. [1] T. Kimura, T. Goto, H. Shintani et al., Nature 426, 5 (2003) [2] Y.-S. Oh, S. Artyukhin J. J. Yang et al., Nature Communications 5, 3201 (2014) [3] J. W. Kim, S. Artyukhin, E.?D. Mun et al., Phys. Rev. Lett. 115, 137201 (2015)