Episode 17: Magic angle enables magnetoelectric switching in multiferroic

In this podcast episode, MRS Bulletin’s Laura Leay interviews Sergey Artyukhin from the Istituto Italiano di Tecnologia and Louis Ponet, who is affiliated with both the Istituto Italiano di Tecnologia and Scuola Normale Superiore di Pisa about a topologically protected switching phenomena in ferroic materials. When a multiferroic crystal (GdMn2O5) is placed in a magnetic field at a very particular angle to a crystallographic axis, and the magnetic field is swept up and down twice, the system switches between four magnetic configurations. The interplay between the spin of the gadolinium and manganese ions leads to a unidirectional rotation of the spins and because this rotation is caused by the up-down sweep of the magnetic field, it can be thought of as a crankshaft. This four-state magnetoelectric switching emerges as a topologically protected boundary between different two-state switching regimes. While this magnetoelectric switching has only been observed in one multiferroic material, modelling can help predict other suitable materials from first principles. Eventually this could lead to new technology. This work was published in a recent issue of Nature (doi:10.1038/s41586-022-04851-6).