I’ve enjoyed standing in for Dr. Oilcan and appreciate his gracious offer to have an experimentalist representative on his guest-blogging squad. As Aaron said, I don’t know how he does it, but whatever juice he’s on, he sets a high bar. The number of posts I had envisioned before I started outnumbers the actual number by about a factor of three, and I’m sure you’re sad at the lack of six more book reviews and at least two interminable posts about rugby (Caltech rugby in particular). Maybe next time.

So, without further ado- stay sweet! Keep in touch!

The reason I bring up state songs is not to bring up the ill-fated campaign to make “Born to Run” the New Jersey state song (this town rips the bones from your back; it’s a death trap, it’s a suicide rap; we’ve gotta get out while we’re young.) but rather to point out that the state I currently work in (but do reside in; I’m taxed but not represented, myself) has its own state song, Maryland, My Maryland! Astounding, jaw-droppingly “war-of-Northern-aggression”-style lyrics below the fold.

The despot’s heel is on thy shore, Maryland!
His torch is at thy temple door, Maryland!
Avenge the patriotic gore
That flecked the streets of Baltimore,
And be the battle queen of yore,
Maryland! My Maryland!
…
I see the blush upon thy cheek,Maryland!
For thou wast ever bravely meek, Maryland!
But lo! there surges forth a shriek,
From hill to hill, from creek to creek,
Potomac calls to Chesapeake,
Maryland! My Maryland!

Thou wilt not yield the Vandal toll, Maryland!
Thou wilt not crook to his control, Maryland!
Better the fire upon thee roll, Better the shot, the blade, the bowl,
Than crucifixion of the Soul,
Maryland! My Maryland!

I hear the distant thunder-hum, Maryland!
The Old Line bugle, fife, and drum, Maryland!
She is not dead, nor deaf, nor dumb-
Huzza! She spurns the Northern scum!
She breathes! She burns! She’ll come! She’ll come!
Maryland! My Maryland!

This is apparently sung to the music of “O Tannenbaum.” I don’t really see how.

But the second-worst blog post in the world is the why haven’t I blogged post, so I’ll shut my trap. An astro friend of mine asked me to post on what I think is really cool in atomic physics these days, which is just too huge of a task to do exhaustively, but I’ll throw out some stuff off the top of my head. I’m sure I’ll forget some wildly important subfield, but I haven’t had my coffee yet and I’m trying to beat Aaron to the next post.

First of all, atomic physics has to a large degree become dominated by the cold atom scene, and one major thrust of that scene is the study of cold atoms into optical lattices. I posted briefly about this stuff before, but the whole concept is one large bridge over to the condensed-matter world: an optical crystal with band structure and site-to-site phase coherence is yowza interdisciplinary, and not just in a use-interdisciplinary-to-get-money way. The windows lattices are giving us into quantum behaviour are simply astounding, from observing single-atom superposition in double-well lattices to quantum gates (mentioned before) and second-order tunnelling. (Full disclosure: there’s some own-group-promotion there.) The traditional CM notion of the Mott insulator zero-temperature phase transition, for example, is a current hotbed of neutral atom optical lattice investigation, as is the idea of using neutrals in a lattice to simulate classically intractable quantum Hamiltonians.

Optical frequency standards and clocks are really hitting their stride now, and the idea of a part in 10^18 stability is not crazy at all. As usual the folks in Colorado are leading the way; an example of the work is here. I don’t see the day approaching anytime soon when the cesium standard at 9 GHz is going to be replaced; if any field has inertia, it’s fundamental unit definition. Maybe in twenty years or so. For a cool exploration of some of the consequences of such good stability, here’s a cool article from Physics Today by Dan Kleppner of MIT.

There’s also strong movement away from classic (10-year-old!) techniques of trapping to so-called “atom-chip” based experiments, where the trapping fields for cold atoms are generated not by big ol’ coils or lasers shining into the cell, but by in-vacuum current-bearing wires combined (perhaps) with strong radiofrequency dressing. It’s a great step to miniaturization and simplification (depending on how you think of simple). Doing macroscopic quantum superposition experiments, for example, becomes much more doable when you move to the chip scale.

They get a lot of publicity, so I won’t say too much about the quantum-information advances in cavity QED and trapped ions, but suffice to say these subfields show no sign of slowing down.

How could I forget fermions? The other huge bridge to condensed-matter physics is a hotbed of activity these days, from people studying phase separation and superfluidity of degenerate Fermi gases (see here , here, and here) to work putting fermions in optical lattices (an example here). You can also put them on atom chips! As much of a boson fellow that I am, I suspect there’s going to be a lot of insight in the next five years coming from the fermion scene, both macroscopic and lattice-based. The large fellow in the corner is high-Tc superconductivity. Please ignore him.

So what did I leave out that’s also cool? Polar molecules and Rydberg atoms are hot right now, as is the cooling of mesoscopic oscillators to the quantum regime; the study of Bose gases in 2D has also seen significant flurries of work lately. And I would be remiss if I didn’t mention that precision measurements, particularly the recent work further refining alpha and the electron magnetic moment, never cease to amaze me.

Please, please forgive me if I did not link to your research group or forgot to mention your subfield. This review was very off-the-cuff.

I’m tragically not in the picture, as I was gone that day, but also wasn’t an author on the paper; the data were taken last summer, before my arrival, which gives you an idea of the delay in this business between data, writing, and publishing. Highlights from the article include us cooling down atoms to -460 Fahrenheit, which if you know your numbers, is below absolute zero. We expect our phone call from Sweden next week, thank you very much.

At the moment I’m sneaking in a few data runs before getting some needed rest; I’m rising early to catch a 6am flight to Oakland, and the BART to Berkeley, to carouse with old chums and watch Cal beat Tennessee. As much as you crave my handicapping insight, I won’t jinx things by offering a spread. I’m a little nervous; the further I’ve gotten from undergrad, the more I’ve become emotionally invested in Cal football. They’ve gotten a lot better since the seven straight Big Game losses that started my sophomore year, so I guess it could be worse– I could be a fan of the (forgive me) L.S. Junior University.

These days we’re a little bit more sophisticated. Computers are indispensable parts of every physics lab, and there’s various pieces of software that have become somewhat ubiquitous. If I ever have the blessing or curse of grad students, here’s what I’d want them to be able to use, and what I try to be useful with myself:

Labview. This venerable suite is ridiculously dominant in the small-lab physics world, and it’s easy to see why. It interfaces with hardware well, has an intuitive feel that is easy to pick up quickly, even as a youngster, and is well-supported and documented. I use it to run experiments, connecting with and programming various analog-to-digital converters, pulse generators, and any number of GPIB devices. Its main drawback is a general sense of aesthetic unpleasantness.

Mathematica. Stephen Wolfram’s squalling baby has become the default tool for so many of my physics needs that despite its steep learning curve it remains second-to-none. It’s a bit more suited to symbolic theoretical analysis and visualization than data processing, which is why for raw data I like to use other packages, like:

Matlab. Great for anything involving numbers, and arrays of numbers. For theoretical work I don’t really know how I’d use it, since it’s not really a symbolic package, but I really like the intuitive way in which it handles arrays. I’ve also been loyal ever since I spent a few months at my pre-PhD job converting old Fortran nested loops into Matlab array operations.

Unfortunately, the culture of my current lab favors another package, Igor, which I initially loathed but have come to at least tolerate. I don’t think anyone out there will start using it from my recommendation, and those of you in the Igor cult are already converted, so I won’t say any more.

For an idea of how it’s all put together, I typically do calculations and modeling (before and after taking data!) for an experiment in Mathematica, take the data using LabView, which sends the raw data to Igor or Matlab to be played with and analyzed; fun times are had by all.

Please commence arcane software flamewars now. Before you tell me, though, I’m fully aware that Mathematica has near-infinite capabilities, and that Python can fully replace the very, very expensive Matlab. Just don’t tell me to use Maple or MathCad.

First off, we have the upcoming anniversary of Katrina, about which Jane Dark has a tough tale to tell:

The abandonment of a great city to time and tide is indeed both symptom and mark of empire on its downhill slide; it bears noting as well that pathetic, delusional and desperate regimes are equally an indicator of this decline.

I’m interested in what she has to say, but Ozymandias references are sooo AP English. She also disses on Stardust here, but I’m not touching that with a ten-foot Worldcon program.

Second, we have gender issues in physics again! One of the former Quantum Diaries bloggers makes a bit of a scene by writing well and interestingly about a Harvard theoretical physicist’s talk on black holes at the LHC, with the unfortunate addition of a detailed look at her clothes, hair, and body. Good times. It’s a good blog otherwise, and worth reading; I’m hoping that this is a either one of those writing-style misunderstandings or a Teaching Moment. Clifford got to it before me, but I’m mentioning it for the three of you who read this blog but not his.

This site says the Los Angeles Dodgers only have a 25% chance of making the playoffs, or thereabouts, which should depress you. The host runs millions of sims daily, basically Monte-Carloing major league baseball. It’s a little weird that each game is a coinflip, but I guess for a first effort it’s at least amusing. What it doesn’t say anything about is why Brad Penny can’t seem to be good in the second half, while everyone knows the age-old conventional wisdom: if you’re 6’5 and 260, you can’t pitch worth a damn after August. So much for another Cy Young.

To fix this horrible depression, you should listen to “C’mon Sea Legs” by The Immaculate Machine. Or just buy the whole damn record. I heard it in a hotel room recovering from exuberance the other morning in a Denver hotel (a Princeton string theorist marrying an MIT biochemist: more brainpower in connubial bliss I have never seen) and it blew my mind.

And that, as they say, is the memo.

Minor spoilers ahead, but no big ones.

I really wanted to love this one. Gibson’s of course been a big part of my life since I was a wee one; Neuromancer is one of the few books I’ve been rereading at every stage of my life since middle school, and getting more out of it each time. In fact, I’ve reread everything of his but the Difference Engine, which is no knock on it. I guess I continually expect big things from the fella.

In case you had been under a rock, his last book, Pattern Recognition, broke out of his near-future mold and set a book in the recent past; effectively present-day. I don’t know whether he’s trying to broaden his toolkit, or whether he found the conventions of genre too binding; regardless, he did well. Pattern Recognition was an paranoid ride through the hypercommercial fully-connected post-90s world. If he struck any false notes, it was that the world of the internets moves quick enough to make his web communities seem…outdated.

And that’s not what’s wrong with Spook Country. He’s made a specific effort to identify a particular vision of 2006, which may or may not age well, but it didn’t bother me. His story is compelling, linking a former rockstar who’s trying out life as a culture writer, a junkie sucked into some spy work of unknown provenance, and a Cuban-trained cloak-and-dagger prodigy thrown into the mix. There’s a macguffin, but it’s a good one.

So why am I feeling sour? First of all, any delight I had when figuring out for myself what was going on when the plot threads all began to merge was ruined when it was explained to me. Not cool. Gibson’s power is in mystery, and in just giving you enough information to think you know what’s going on, and no more. To boot, there’s a constant sense (particularly as he’s introducing side characters) that he’s trying a little too hard to generate edge. This edge was there in Pattern Recognition, but was genuine. Here, I’m not so sure. But maybe he’s not writing for me anymore.

I was also peeved when a character from Pattern Recognition returned (which is fine, although I thought he was trying to break out of genre, and shared-universe novels?) and referred to the events in that book in a very annoying as-you-know nod to the reader. I’m a big fan of Gibson’s creation Hubertus Bigend, and the things he does, but some subtlety would be appreciated.

What can you do, though? There’s moments of wonder, and Gibson’s still good at building a mystery, and I’ll still buy him in hardcover. If I’ve got too much instinct to poke behind the curtain, it’s probably my fault.

(This post was written as if I was in his novel: on my OS X laptop, listening to post-something on my iPod, flying the Monday-night business connection from Newark to Reagan: a plane filled with spooks, salarymen, and students. All I needed would have been a briefcase full of data and maybe a video artist paramour and it would really have gotten eerie. )

I have a couple half-days to kill while I’m there…any recommendations for things to do in Denver when you’re there?

Fiction for the plane: (I’m bringing some papers to read, too, and some paper and pen for an outline I need to make, but the best laid plans…)

Taltos, by Steven Brust. I’m rereading his Vlad books. I remember this one being one of my favorites, so I’m looking forward to it.

Rubicon Beach, by Steve Erickson. A kind-of obscure guy, recommended to me. We’ll see how it goes.

Anton Zeilinger (Vienna) has a blog. It’s in German, but that shouldn’t be a problem, right?

I found that out at Michael Nielsen’s place, where he’s started blogging again after a little hiatus.

In an effort to improve on my bibdesk+bibtex+folder-full-of-local-pdfs system, I’ve been playing around citeulike, Papers, and Nielsen’s Academic Reader. Papers is crippled for physicists by its sole reliance on PubMed for metadata, but shows a lot of potential. I’m also definitely curious to see where Academic Reader goes as it grows; as it’s being developed by physics people, it should end up being the optimum solution…

Street Anatomy is a medical illustration blog. It’s cooler than it sounds; you should browse through the archives.

I probably don’t need to tell this scene about LibraryThing, but in case you haven’t been there and played around with what they’re doing, you should. It’s an indispensable site for me now, both for keeping track of my own books and for getting word of ones I should get.

Finally, and unrelated, when Stephen King reviews the last Harry Potter book and refers to the epilogue as being “gorgeous” (thanks, Galley Slaves), I don’t know what to say. A friend said that it read like a teenager’s first attempt at fanfic, and I agree.

I epoxied some stuff onto some other stuff. More importantly, I calculated a band structure.

This amazes me. Sure, all you squa^Wsolid-state types out there do this every day, over your cereal even, and (in some cases) just have it done for you by the undergrad, but I’m an AMO physicist. I haven’t calculated a band structure since I first made sweet love to the Kronig-Penney potential back in the warrens of LeConte and Campbell, guided by the two-who-are-one, Cohen and Tannoudji. But I’m doing AMO, and band structure is a big part of my life now. What gives? Am I moonlighting on the side in some semiconductor fab trying to make a few bucks?

Hardly. See, solid-state physicists are interested in energy band structure because it’s a basic description of how electrons move in the periodic potential that is the crystal lattice in which they reside. An electron in a crystal moving about sees a nice orderly area of whoa-deep wells, and if we think about this quantum-mechanically, we realize that there’s a neat solution involving delocalized states known as Bloch wavefunctions, allowing the electron to do all the things we know and love, as long as it stays within energy bands whose shape depends on the particulars of the lattice in question.

Blah, blah, blah: electrons, crystals, Brillouin zones, reciprocal lattices– this stuff used to bore me to tears. I cared more about cleverly making bosons cold in a single macroscopic potential well rather than dealing with a Fermi gas of charged particles (how messy!) in a nanoscale lattice. Granted, I had a thesis to write, but I regret my single-mindedness. Now! Now I get to put cold neutral atoms into a lattice of my own design, for liberal interpretations of my and design. This is a big subfield of atomic physics these days, even– the construction and use of so-called optical lattices to explore quantum mechanics and (by construction) condensed-matter physics in a system that’s clean and customizable in ways that, um, Bardeen or…Onnes? could ever have imagined.

So what’s the secret? Neutral atoms have electrons in them, in some groundstate orbital. Alkalis (like rubidium) have a single valence electron, which gives them the nice characteristic of having decent electric and magnetic dipole moments. The magnetic dipole moment is useful for making magnetic traps, whereby you make a spatial minimum in magnetic field, which a weak-field-seeking atom sees as a bowl. The electric dipole moment is useful because it means the atom can be electrically polarized, meaning it’s happier in a region with intense electric fields, which conveniently can be made with lasers.

So that’s how we make a custom-built periodic potential for neutral atoms: we take a beam of focused laser light, reflect it upon itself to form a standing wave of constructive and destructive interference, and the atoms see regions of high intensity as valleys and dark regions as hills. Of course, this periodic potential is hundreds-of-nm scale instead of the nm-scale in, say, some sort of grotesque ruthenate, but that’s just a quibble. In my lab we have an analogue condensed-matter system with tunable tunnel couplings, temperature, band population, band structure, and even (thanks to BEC) phase coherence. And maybe one day, impurities that aren’t holes. More importantly, via time-of-flight imaging, we have access to the momentum distribution of the atoms in the lattice…but that’s a whole ‘nother bag of worms.

The setup I just told you about generates a 1-d sinusoidal potential, whose band structure isn’t rocket science. But with more and more beams you can do more and more Fourier components, and the can of tricks really opens up from there, in terms of interesting single-well geometries, and interesting band structures. The upshot: even though I have nothing but ultracold alkali vapor, a laser, and a few mirrors, I can justify the purchase of my own copy of Kittel.