## Wednesday, September 30, 2015

### DOE Experimental Condensed Matter Physics PI Meeting 2015 - Day 3

Things I learned from the last (half)day of the DOE PI meeting:
• "vortex explosion" would be a good name for a 1980s metal band.
• Pulsed high fields make possible some really amazing measurements in both high $T_{\mathrm{C}}$ materials and more exotic things like SmB6.
• Looking at structural defects (twinning) and magnetic structural issues (spin orientation domain walls) can give insights into complicated issues in pnictide superconductors.
• Excitons can be a nice system for looking at coherence phenomena ordinarily seen in cold atom systems.  See here and here.  Theory proposes that you could play with these at room temperature with the right material system.
• Thermal gradients can drive spin currents even in insulating paramagnets, and these can be measured with techniques that could be performed down to small length scales.
• Very general symmetry considerations when discussing competing ordered states (superconductivity, charge density wave order, spin density wave order) can lead to testable predictions.
• Hybrid, monocrystalline nanoparticles combining metals and semiconductors are very pretty and can let you drive physical processes based on the properties of both material systems.

Doru Constantin said...

Thanks for this interesting list! In the last link you may want to replace "dx/doi" by "dx.doi", otherwise it does not resolve.

Douglas Natelson said...

Fixed - Thanks!

Anonymous said...

Am I the only one who wonders whether any branch of physics is relevant to practical matters of commerce?

Douglas Natelson said...

Well, condensed matter physics is directly relevant to many aspects of whatever internet device you used to post that comment, is responsible for all the computer hardware that runs the modern world, etc. Atomic physics is directly relevant to things like GPS.

Anonymous said...

Yeah, but I'm talking about lately, not historically. Some of the crony capitalists of Wall Street no longer have a high opinion of physicists. See this fool here:

"My formal training was in physics, where, generally speaking, statistical sophistication is fairly low. Physicists have the luxury of being able to construct experiments where the observation of one or two photons or some preposterously small amount of torque on a magnetometer is meaningful. Pretty much nobody but physicists have this luxury.

Physicists no longer have this luxury for the most interesting problems these days. Unfortunately nobody told them, which is why physics has been languishing in the swamplands, with “physicists” working on non falsifiable noodle theory, cosmology and writing software for computer architectures which will probably never exist."

Tahir said...

Dear Anon at 9:56,

First of all, I would like to mention that almost all of the invaluable contributions which Doug listed were not targeted or strategic discoveries that were planned out, but were serendipitous consequences of random curiosity-driven ventures. Research, by definition, cannot be done on a schedule with predictable results, so anyone asking why physicists (or any other scientists) doing basic research are not working on practical matters is demonstrated a fundamental (and, unfortunately, wide-spread) misunderstanding of the way basic research works. As Mermin said, "I am waiting for the day when people realize that discovery does not work by deciding what you want to discover and then finding it." For what it's worth, David Botstein, one of the leading pioneers of genetics, whose discoveries have had tremendous far-reaching effects on medicine and biotechnology, echos my sentiment: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484092/ , so this is not just some crazy excuse by an outlandish physicist, but an indisputable fact about the way basic research, which is the lifeblood behind almost all contemporary technology and commerce, operates.

Second, even leaving aside what I just said, it is simply empirically, factually, incorrect that physicists today are not working on areas that have the potential for 'real-world' application. Consider the program for the upcoming APS March Meeting, the largest conference of physicists in the world: http://www.aps.org/meetings/march/scientific/categories.cfm#12 Almost every section deals with a topic that is either directly related to applying physics to real world problems, or is developing the science behind novel materials/biological systems with downstream relevance to industrial engineering. I mean, what more do you want?

If anything, I think nowadays, physicists, and other scientists, are put under too much pressure to make their work directly applicable. Scientific exploration is being treated like a business, often by people who have no understanding that it is precisely not a business.