According to conventional physics, electrons flowing through metals like iron, nickel, and other potentially magnetic materials act in a manner similar to “little bar magnets.” In essence, once electrons are introduced to extremely low temperatures, they begin to align themselves, pointing in the same direction within large “domains” in crystalline matter. What conventional physics can’t explain is exactly why the electrons align themselves.
Now, according to a new study performed by So Gyu-Boong Jo, Wolfgang Ketterle, and several of their colleagues at the Massachusetts Institute of Technology in Cambridge, an ultra-cold gas has been observed self-magnetizing in a similar way, according to a team of atomic physicists. What this shows us is: the “messy physics” observed in solids can be modeled with the observation of pristine gases, the researchers say. This fascinating study poses the question: is it possible to magnetize a gas?
Though some in the scientific community are saying the new study’s observations are still questionable, the answer as to why electrons may behave in this manner was already proposed eighty years ago by British theorist E. C. Stoner. Using the the Pauli exclusion principle as a model (stating that no two identical fermions (electrons in this case) may occupy the same quantum state simultaneously) Stoner supposed that if the electrons repel each other with enough force, they could lower their total energy by aligning. Gas could become agitated by the flipping of select electrons, increasing its kinetic energy. Since Pauli’s exclusion principle says no two aligned electrons could be in the same place at the same time, electrons would avoid each other, according to Stoner, further reducing energy loss between electrons in close quarters.
Stoner designed an equation that explained this “ferromagnetism”, though it has never been conclusively proven. Ketterle their colleagues at Cambridge thus decided to see if they could use “puffs” of lithium-6 atoms to do so. To read more about their innovative research, follow this link:
Magnetized Gas Points to New Physicsby