When you make conducting wires thinner, their electrical resistance goes up. This is Ohm's law, and it is generally right. An important exception is at very low temperatures, where the mobility of electrons increases when wires become so thin that they are effectively two-dimensional. Now, University of Groningen physicists, together with colleagues at Brest University have observed that something similar happens with the conductivity of magnons, spin waves that travel through magnetic insulators, much like a wave through a stadium. The increase in conductivity was spectacular, and occurred at ambient room temperature. This observation was published in Nature Materials on September 22.