I don't understand how someone can create a page like this and not find it necessary to explain the name<p><a href="http://en.wikipedia.org/wiki/Almost_Mathieu_operator" rel="nofollow">http://en.wikipedia.org/wiki/Almost_Mathieu_operator</a>
Some very cool physics involved-- a lot of basic quantum mechanics (electrons hopping on a lattice), but it has a lot of really broad implications about symmetries. There is a lot of recent interest in the butterfly [1,2].<p>It turns out that it is a very important state to study the Quantum Hall effect[3], and the fractional Quantum Hall effect[4], which seem to be in vogue in Condensed Matter physics these days.<p>Sorry to bog you down with details, I just wanted to mention how neat it is that Hofstadter's butterfly is still being studied today!<p>[1] <a href="http://www.nature.com/nature/journal/v497/n7451/full/nature12186.html" rel="nofollow">http://www.nature.com/nature/journal/v497/n7451/full/nature1...</a>
[2] <a href="http://physics.aps.org/articles/v6/118" rel="nofollow">http://physics.aps.org/articles/v6/118</a>
Hope I am not the only one that thought this had something to do with Leonard...
<a href="http://en.wikipedia.org/wiki/Leonard_Hofstadter" rel="nofollow">http://en.wikipedia.org/wiki/Leonard_Hofstadter</a>