We’ve just gotten word that one of our papers has been accepted to Physical Review Letters. The preprint is available here on the arXiv servers : cond-mat : 0909.2273. The paper deals with our work on studying the surface reconstruction of gold using coherent scattering techniques.

The short story is that we’re able to get access to how quickly the microstate (the microscopic configuration and profile of the surface) is evolving even when the average properties of the surface are not changing. We’ve been able to collect speckled scattering patterns and, by comparing how fast the speckles evolve, determine some new information about the surface dynamics. This was principally a demonstration experiment that happened to have some nice results along with it. We’re now working to extend this technique to a few new samples and system combinations.

Surprisingly I did not have my usual multi-hour fight with the arXiv server either. Usually it takes countless attempts, anger, meditation, bribery, and some things I should not admit in order to get through the automated paper submission process. But for some reason this time it happened without a hitch.

One of the fun things about papers is creating the figures. Well, sometimes it is fun, and sometimes it is tedium. However, the results are sometimes quite nice. The little thing above is a ray-tracing example or ``cartoon” of the two different surface orientations of a hexagonal arrangement over the square facet of a face centered cubic arrangement.

Actually, that’s a nice way to begin to explain the header graphic for the blog (at least the current one). If you notice the two hexagons are offset from each other by a rotation of 30 degrees (it’s actually a 90 deg rotation, but 30, 90, 150, etc... are all the same. That is called symmetry, but it takes too much digression for the moment). Each hexagon has 6 corners. Though for our purpose, it’s better to think of each hexagon as having 6 possible orientations. But since there are two was of laying the hexagons down over the squares, you get 12 total possible orientations. These orientations can all be made to satisfy a diffraction condition.

The graphic below is an example (albeit a computer generated one) of what such a diffraction patter would look like.

There’s a bright region in the center, but let’s ignore that for a moment. Instead, count the number of bright spots going around in a large circle. There are 12, one for each of the possible orientations. To be fair, this picture is as if we are diffracting photons through the sample, instead of off of the sample (we reflect them).