Sunday, January 25, 2009

Nonlinear Electron Waves for Pedestrians:

Besides Nuntiya's posted "Huh?", I've gotten a few (unposted) comments by email that it might be a good idea not to completely snow all my readers at the first opportunity. So this posting is meant to kind-of sort-of explain what was in the previous post. (Doug and Ilya and any other condensed matter physics people reading this, please don't shoot me for oversimplifying, I just started teaching this month so that's my excuse why I'm not so good at simple explanations).

Imagine a large tub of Jell-O. If you punch it, waves will jiggle outward from where you punched it. (See the cute animation on this page). This is a typical response of most materials. Although it is not so easy to see, the same thing happens when you hit a rock, or a steel girder. Electrons do the same thing. If you think of the electrons in a material as forming a jell-o like fluid (and ignore all the nuclei of atoms that are sitting still while the electrons are doing there thing), when you hit the electrons, electronic waves will emanate out from where you hit them.

If you think about waves moving in the ocean, you know that their structure slowly changes. Some waves get bigger, others smaller, sometimes they merge, sometimes they split. The claim made in the previous posting is that the electron waves (in fractional quantum Hall systems of electrons -- never mind what this means) evolve in such a way that they end up looking like individual sharp pulses, each carrying a particular amount of electronic charge. Of course it would be really nice if each pulse carried one single electron worth of electronic charge. But in fact, the claim is that each pulse carries a third of an electron, each electron having "fractionalized" into three pieces. There are other odd and interesting things about the electron waves in questions that I'm sweeping under the rug too, but that is the general idea.

Unfortunately, this proposal disagrees with the accepted dogma of the scientific community. However, it only disagrees a bit and it seems within the realm of those things that might actually be right. If I had to bet right now, I'd give it about a 1 in 5 shot of being right. But 1 in 5 is pretty good when you are talking about overturning 20 years of study.

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