Last week’s post talked about the general idea of negative temperature, with reference to this much-talked-about Science paper (which also comes in a free arxiv version from which the figures used here are taken). I didn’t go into the details of how they made a negative temperature gas, though, and as it’s both very clever… Continue reading How Do You Make Negative Temperatures, Anyway?
Category: Condensed Matter
What Does “Negative Temperature” Mean, Anyway?
The most talked-about physics paper last week was probably Negative Absolute Temperature for Motional Degrees of Freedom (that link goes to the paywalled journal; there’s also a free arxiv preprint from which the above figure is taken). It’s a catchy but easily misinterpreted title– Negative absolute temperature! Below Absolute Zero! Thermodynamics is wrong!– that obscures… Continue reading What Does “Negative Temperature” Mean, Anyway?
The “Ballistic” Story
Last week, in the post about fermion conduction, I left a reference hanging: There’s nothing physically blocking the atoms from flying right through the channel– in fact, an atom that enters the channel will always exit the other side without slowing down along the way. This is termed “ballistic,” a term that will always have… Continue reading The “Ballistic” Story
Simulating Wires with Atoms and Light: “Conduction of Ultracold Fermions Through a Mesoscopic Channel”
So, it’s been a while, but let’s see if we can’t hit the ground running with a good physics post. There have been a few notable physics events since I went on hiatus, but for a return to physics ResearchBlogging, we’ll go with something near and dear to my heart, ultracold atoms. Specifically, this Science… Continue reading Simulating Wires with Atoms and Light: “Conduction of Ultracold Fermions Through a Mesoscopic Channel”
On the Interconnectedness of Things
I finally got a copy of Cox and Forshaw’s The Quantum Universe, and a little time to read it, in hopes that it would shed some light on the great electron state controversy. I haven’t finished the book, but I got through the relevant chapter and, well, it doesn’t, really. That is, the discussion in… Continue reading On the Interconnectedness of Things
Strongly Correlated Physics in a Superposition State
It’s been a while since I posted anything science-y, and I’ve got some time between flipping pancakes, so here’s an odd thing from the last few weeks of science news. Last week, there was an article in Nature about the wonders of string theory applied to condensed matter physics. This uses the “AdS/CFT” relationship, by… Continue reading Strongly Correlated Physics in a Superposition State
The Physics of Frustration: “Quantum Simulation of Frustrated Classical Magnetism in Triangular Optical Lattices”
One of the benefits of having joined AAAS in order to get a reduced registration fee at their meeting is that I now have online access to Science at home. Including the Science Express advance online papers, which I don’t usually get on campus. Which means that I get the chance to talk about the… Continue reading The Physics of Frustration: “Quantum Simulation of Frustrated Classical Magnetism in Triangular Optical Lattices”
What’s So Interesting About Ultracold Matter?
The first of the five categories of active research at DAMOP that I described in yesterday’s post is “Ultracold Matter.” The starting point for this category of research is laser cooling to get a gas of atoms down to microkelvin temperatures (that is, a few millionths of a degree above absolute zero. Evaporative cooling can… Continue reading What’s So Interesting About Ultracold Matter?
What’s So Interesting About AMO Physics?
That’s the title of my slightly insane talk at the DAMOP (Division of Atomic, Molecular, and Optical Physics of the American Physical Society) conference a couple of weeks ago, summarizing current topics of interest in Atomic, Molecular, and Optical Physics. I’ll re-embed the slides at the end of this post, for anyone who missed my… Continue reading What’s So Interesting About AMO Physics?
What’s So Interesting About AMO Physics?
That’s the title of my talk this morning at DAMOP, where I attempt the slightly insane feat of summarizing a meeting with over 1000 presentations in a single 30-minute talk. This will necessarily involve talking a little bit like the person reading the legal notices at the end of a car commercial, and a few… Continue reading What’s So Interesting About AMO Physics?