Oct 9, 2010

Nobel Prize of Physics for Graphene

I know news run fast through the web and everyone knows by now that the Nobel of physics this year went to Andre Geim and Konstantin Novoselov, from the University of Manchester here in the UK, for the discovery/invention of graphene. As usual, it was a busy week and the only thing I had time to do about it was to put together a gallery of graphene pictures on my other blog Sciencescapes. And probably everyone also knows by now that Andre Geim won the IgNobel prize of physics in 2000 for levitating a frog over a superconducting magnet. The frog paper is free to read: Of Flying Frogs and Levitrons,  by M.V. Berry and A.K. Geim, European Journal of Physics 18, 307 (1997) .

Graphene is a very interesting material. It is the closest you can get to a two-dimensional sheet  for it is a carbon sheet just one atom thick. The picture above is an artistic rendering you can find on Wikipedia. It shows that graphene forms what we call a regular hexagonal lattice. I should have written in this blog about that before, because I always thought these guys would win a Nobel soon, but now I cannot prove it. It was somewhat logical to assume it as if you check the condensed matter part of arXiv daily, you will see that it is hard to find a day without a paper about graphene. 

Due to the fact that it is practically two-dimensional, graphene has many interesting physical properties. In particular, at least for physicists, you can find an anomalous quantum Hall effect. Also, being 2D, graphene can support anyonic quasi-particles, elementary excitations that have statistics which are neither bosonic nor fermionic (see the previous post Anyons). As an extra bonus, graphene appears to be one of the strongest materials that exists, with a breaking strength 200 times greater than steel.

Geim, Novoselov and others wrote a nice review on graphene: The electronic properties of graphene, Neto et al., Reviews of Modern Physics 81, 109 (2009).  There is also this other paper by Peres: The transport properties of graphene: An introduction, Peres, Reviews of Modern Physics 82, 2673 (2010). Unfortunately, you need a subscription to access them. 

As I lost the opportunity to predict the graphene Nobel, this time I will take the risk of making the prediction (which is again fairly obvious) that soon the Nobel will be given to the guys who discovered that the universe expansion is accelerating. They were called the High-z Supernova Search Team, and the discovery came on 1998. Adam Riess was the leader of the team, so he is probably one of the guys who will win the prize. That discovery was completely a surprise at the time as everyone were expecting a decelerating universe. This also led to many famous hypothesis to try to explain it, like dark energy and quintessence.

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