Remote Cooling with Magnets
Magnets have quite a number of uses, from entertaining and educating students to storing data. Magnetism itself is the result of the magnetic moments, or spins of particles in a material aligning. Researchers at MIT have recently found a phenomenon to do with magnons that can be used to cool magnets, remotely by a magnetic field.
Magnons are quasiparticles representing the collective spins of particles within a magnet. These quasiparticles are able to move through a magnetic when exposed to a magnetic field gradient. What the MIT researchers realized is that when the magnons move, they take heat with them, cooling part of the magnet. From this idea they built a theoretical model based on the Boltzmann transport equation, which has to do with electron transport in thermoelectrics, and plugged in numbers found in previous research papers. The results suggest that though small, the effect does create a cooling effect from a moderate magnetic field gradient.
Currently this work is purely theoretical, so we cannot expect to be cooling our electronics with it any time soon. It will likely first find a use in cryogenic systems, as the effect is more pronounced at low temperatures.