Figure 1: Sketch of a magnetoelectric write head for magnetic hard disk (after A. K. Zvezdin [5]). An electric field $\mathbf{\text{E}}$ generates a bulk magnetic moment $\mathrm{\Delta }{m}_{\text{ME}}$ in a slab of magnetoelectric material, thus giving rise to a magnetic flux density $\mathbf{\text{B}}$. The gap in the flux closing yoke emits a stray field, which writes a magnetic “bit” into the moving track (velocity $\nu$) of the hard disk.