DAMOP Day 2

One of the odd things about going to conferences is the unpredictable difference between talks and papers. Sometimes, when you go to a talk, you just get an exact repetition of what’s in the paper; other times, you get a new angle on it, or some different visual representations that make something that previously seemed dry and abstract really click. And, of course, sometimes you get new hot-off-the-apparatus results that haven’t made it into print yet.

Maddeningly, there doesn’t seem to be any way to know in advance which of these things you’re going to get from the title and abstract. It helps to know the speakers– some people give reliably excellent talks, that will be worth seeing whether they have new results to report or not. There are lots of other cases, though, and inevitably lots of speakers that you know nothing about beyond their name and affiliation, so it’s kind of a crapshoot.

Of course, this problem can be dodged very effectlvely by being completely out of touch with the state of current research. That’s my usual condition these days, particularly when DAMOP takes place during the academic year. Because of my insane survey talk, though, I’ve spent the last couple of weeks reading (well, skimming) lots of research papers, which has led to a larger than usual number of talks where I left saying “Well, that was a nice talk, but there wasn’t anything new there…

Yesterday morning, I went to the session on NV centers, but a couple of annoying issues cropped up that required me to spend most of Misha Lukin’s invited talk dealing with email, and I was deeply distracted for the rest of the session.

In the 10:30 block, I went to the session on Fundamental Symmetry Tests, which was fantastic, and included a number of things I’ve blogged about before. Ernst Rasel talked about dropping BEC’s, which included a note that the up to 50g acceleration their apparatus experiences when landing was “less problematic than expected,” meaning that everything stays aligned and operates normally right after landing. Randolf Pohl gave an excellent talk about the proton size measurement, in which he downplayed the discrepancy somewhat, suggesting that there are some reasonable ways to adjust the analyses of other experiments to bring the old values in line with their new value; this won’t endear him to either the other experimentalists, or the theorists who are inventing new physics to explain the difference, but he made what sounded like a decent case. Ekkehard Peik talked about looking for the thorium nuclear transition in the UV that led me to dreadful punning, and James Chou talked about the NIST ion trap clocks that show relativistic shifts on everyday scales. In response to a question, he noted that future definitions of the second based on these sort of ultra-precise clocks might well need to specify an altitude as part of the standard, which is just amazing.

In the afternoon, I went to the quantum communications session, where Richard Hughes gave a talk about Los Alamos’s progress toward doing quantum cryptography between satellites and ground stations, where they’ve apparently done everything but find somebody willing to put a laser system in space so they can test this. The speaker from the Chinese group that has demonstrated quantum teleportation through 16km of open air didn’t show up– I imagine he got entangled in some sort of travel bureaucracy. I was kind of annoyed by this, since I specifically highlighted that experiment in my talk, but what can you do? Alex Kuzmich gave a very comprehensive history of their progress toward making a “quantum repeater” for extending quantum communications networks, whichinvolves some very complicated and impressive work in both the storage of quantum information in cold-atom clouds, and the transmission of this information through conversion to telecom wavelengths. They can demonstrate a five-sigma violation of Bell’s inequality after several milliseconds of storage followed by up- and down-conversion of the photon wavelength, which is amazing.

I skipped out after that to rest up a bit for the poster session and then the undergraduate institution reception that I organized. The reception went very well, especially given how distant the room was from the main conference area, and I suspect that if I had acted early enough to get it in the printed programs, it would’ve drawn even more people. Maybe next year.