Friday, July 16, 2010

Much Ado About Topological Insulators

Topological Insulators are HOT. They are the hottest thing in condensed matter physics right now. This news summary from Nature describes what they are, and why they are the 'star' material at this moment (link open only for a limited time).

Those effects go beyond the way electrons move on the surface. For example, all electrons are spinning in a quantum mechanical way. Usually, the spins are constantly knocked about by random collisions and stray magnetic fields. But spinning electrons on the surface of a topological insulator are protected from disruption by quantum effects. This could make the materials beneficial for spin-related electronics, which would use the orientation of the electron spin to encode information, thereby opening up a whole new realm of computer technology.
Researchers also believe that the collective motions of electrons inside topological insulators will mimic several of the never-before-seen particles predicted by high-energy physicists. Among them are axions, hypothetical particles predicted in the 1970s; magnetic monopoles, single points of north and south magnetism; and Majorana particles — massless, chargeless entities that can serve as their own antiparticles.

This mimicry is not entirely surprising. Almost by definition, collective electron motions can be described by just a handful of variables obeying simple equations, says Frank Wilczek, a Nobel-prizewinning particle physicist at the Massachusetts Institute of Technology in Cambridge. "There are only a few kinds of equations that you can write down that are really simple," he says. So topological-insulator theorists and particle physicists have almost inevitably ended up in the same place.

In other words, once again, the physics that governs things in condensed matter now have implications into other areas that may be fundamental in nature! How many times have I indicated this already?

And since we're talking about topological insulators, don't miss the latest STM study on something similar that has produced quite an interesting result.


1 comment:

Doug said...

Respectfully, I would suggest a different interpretation. As the example of the Majorana particle demonstrates, condensed matter is getting a boost from the theory underlying hep-theory.

More importantly, this demonstrates that all sectors of basic research (esp. in Physics) are worth investment. You never know when a theoretical idea or technology will cross-pollinate across the field and create new possibilities for condensed matter, particle physics, astrophysics, etc.

A thought to ponder: We all benefit if we talk to each other across fields more, speeding the flow of ideas and technology. Yet we find each other's seminars painful and incomprehensible. How do we improve lines of communication?