  We demonstrate that by combining permanent electric and magnetic moments in
particles, it is possible to realize a new type of medium that allows for a
cross-correlation between electric and magnetic properties of matter, known as
magnetoelectric coupling. Magnetoelectric materials have so far been restricted
to systems that exhibit long-range order in their electric and magnetic
moments. Here, we show that a room-temperature, switchable magnetoelectric can
be realized that is naturally disordered. The building blocks are Tellegen
particles that orient in either an electric or a magnetic field.
