Friday, May 27, 2011

Summer research: High-Tc Superconductors

As you know, I am currently working on my physics Ph.D. with a specialization in condensed matter.  I am finally starting research this summer, next week in fact.  My research project is on one of the hottest topics in condensed matter physics, High-Temperature Superconductors.

I've written about superconductors before, but in case you're too lazy to read that...  *clears throat*

Just like many liquids freeze below a certain temperature, there are some materials which change into superconductors below a certain temperature (that temperature is called Tc).  They won't look any different, but they have awesome properties like zero electrical resistance and magnetic levitation (which are used in MRIs and maglev trains respectively).  For the earliest discovered superconductors, Tc was 30 degrees above absolute zero (-243 Celsius), but so-called High-Tc Superconductors have a Tc as high as 135 degrees above absolute zero (-138 Celsius).  Which is still very cold.  Many physicists seek to understand High-Tc Superconductors with the dream of discovering superconductors at room temperature.

More specifically, I will be investigating superconductors through the use of the ARPES method.  ARPES stands for angle-resolved photoemission spectroscopy.  ARPES involves shooting a photon at the material, and looking at the electrons that pop out.  It's a lot like the photoelectric effect experiment which won Einstein his Nobel prize.

But ARPES is a little more sophisticated, because it doesn't just measure the energy of the electrons that come out, it also measures the angle at which they come out.  The angle tells you about the electron's momentum.  And so we can plot graphs of energy vs momentum.  This is a graph of the electronic band structure, which is of such great importance that I don't know how to properly convey it.  One of these days I will write a better explanation for lay people.  For now, remember those energy bands which were so crucial to the understanding of conductors, insulators, and semiconductors?  Those energy bands are merely a simplified form of the electronic band structure.

Note that I haven't yet fully described my research project; ARPES plus Superconductors is way too broad for a single research project.  But that's just as well, as I don't start until next week.  Perhaps I will write more then, and say something about what exactly I'm doing in the lab.

Though, if it's anything like previous summers, I will probably never fully describe my research here, and instead opt for inside jokes.

1 comment:

Jachra said...

Awesome, I've always been interested in advancements in this field. The potential applications are truly astounding.