Wednesday, May 10, 2006

Chandra Raman's talk

Yesterday we had a talk by Chandra Raman, from Georgia Tech. He showed pictures of vortex lattices in a Bose-Einstein condensate, which he created by stirring the BEC, for example via a laser.

He also discussed their use of Bragg scattering to characterize the condensate, and also how they plugged the trap for Na BECs to counteract Majorana transitions.

Sadly, this was the last talk and lunch of the academic year...and I think it's also my last blog posting for a while, as my hit counter says that this blog has had zero hits thus far, except for a few hits coming from Harvard (i.e., me). :)

I suppose I could discuss Britney Spears in order to stimulate some discussion. :) But that's OK.

Tuesday, May 02, 2006


Here is a link to the Sarong Theorem Archive, a collection of pictures of people wearing sarongs while proving theorems. You too can be immortalized; just send them your picture while proving a theorem, and wearing a sarong.

More Jobs

I just came across another list of jobs available in quantum control/quantum information and related fields.

In the Harvard advertisement, many of the professors listed work at the interface of AMO and condensed matter, which seems to be a very promising field: one reason people are so interested in optical lattices is their potential for exploring phenomena in condensed matter.

Charlie Marcus' group, and in particular Jason Petta, whom I don't know personally, has recently done some incredible experimental work on manipulating electron spins in double quantum dots--worth a look!

Preprint of the day--Quantum chemistry meets quantum computing

Here is the preprint which I would like to highlight today, by Alán Aspuru-Guzik, Anthony Dutoi, Peter Love, and Martin Head-Gordon.

Alán Aspuru-Guzik is coming to Harvard in July, which I think will make him the first real electronic structure theorist here. Electronic structure has been a very hot, and useful, field for a very long time, and I have always been surprised that Harvard did not have anyone in the chemistry department working on it.

The theme of recent research by Alán and some others in the Head-Gordon group has been to use classical computers to simulate quantum computers, and show that quantum computational algorithms can be useful and accurate for determining ground-state energies of small molecules. For example, they have simulated calculations of the ground state energies of both water and lithium hydride. It seems that only a few hundred qubits can give extremely accurate results. Another use for quantum computing!

Now if we AMO people could just get the quantum computer running... :)

Thursday, April 27, 2006

Upcoming AMO Conferences

Upcoming AMO conferences (including theory) are DAMOP (Knoxville, TN) and ICAP (Innsbruck, Austria). Note that the ICAP chairs include Rudolf Grimm, whose work on Efimov states I had mentioned earlier this month.

I unfortunately have to skip DAMOP this time around, as I'm busy in the last few months of my Ph.D. I'm sad about missing DAMOP--like March Meeting, it's very big, but the upshot is that something interesting is always going on, and absolutely everyone you could possibly want to talk to in AMO physics is there. It's therefore great fun to go.

DAMOP 2004 was in Tucson, Arizona in May. The desert was gorgeous--and the U of Arizona is world reknowned for optics. But boy, was it HOT! Those of us from Boston who had forgotten what the sun looked like had to scurry from building to building trying not to melt. :)

DAMOP 2005 was in Lincoln, Nebraska. This year DAMOP is in Knoxville, Tennessee.

This particular atomic physicist hopes for DAMOP 2007 (which I will definitely attend) in Hawaii. :)

Wednesday, April 26, 2006

Graduate Student Etiquette

We recently had a fun (and crowded) talk here by Jorge Cham from Caltech about his comic strip, "Piled Higher and Deeper". (The comic is about graduate school--talk about a niche audience!)

I guess Dr. Cham will never have any trouble filling out the "outreach" section on his grant applications! :)

Anyway, my personal rules of physics graduate student etiquette are this:

Thou shalt not...

1. Ask any physics graduate student what year s/he is in
2. Ask any physics graduate student when s/he is graduating

If the student is eager to volunteer this information, s/he will!

Tuesday, April 25, 2006

Today's talk on Matter Wave Optics

Today we had lunch with, and then attended a talk by, Markus Oberthaler from Heidelberg.

Oberthaler's group is doing very interesting work in BEC dynamics. Today's talk discussed, among other things, dynamics of BECs in shallow and deep periodic potentials, as well as tunneling of a BEC trapped in a double well potential (see cond-mat/0411757). I particularly liked the analogy of the wavefunction in a well to a pendulum with a length dependent on the angular momentum. The double well was created by superimposing a harmonic and periodic potential. Double wells seem quite popular lately, and are also a focus of research by Bill Phillips' group at NIST.

The phenomenon that Oberthaler discussed in connection with the deep potential well was "nonlinear self-trapping," where a wavepacket expands initially, but then stops.