Quantum Optics

Category archives for Quantum Optics

Two papers with a similar theme crossed my social media feeds in the last couple of days. You might think this is just a weird coincidence, but I’m choosing to take it as a sign to write about them for the blog. So, what are these papers, and what’s the theme? One is the final…

Quantum Erasure

When I posted congratulating the winner of this year’s Nobel betting pool, I received a gentle reminder in email that I’m a Bad Person and still haven’t done one of the posts I owe to the 2011 winners. Evan reminded me that he asked for something about the delayed-choice quantum eraser, so let’s talk about…

When Is a Composite Object a Particle?

Through some kind of weird synchronicity, the title question came up twice yesterday, once in a comment to my TED@NYC talk post, and the second time on Twitter, in a conversation with a person whose account is protected, thus rendering it un-link-able. Trust me. The question is one of those things that you don’t necessarily…

Laser-Cooled Atoms: Cesium

Element: Cesium (Cs) Atomic Number: 55 Mass: One stable isotope, mass 133 amu. Laser cooling wavelength: 854nm, but see below. Doppler cooling limit: 125 μK. Chemical classification: Yet another alkali metal, column I of the periodic table. This one isn’t greyish, though! It’s kind of gold color. Still explodes violently in water, though. Other properties…

Laser-Cooled Atoms: Strontium

Element: Strontium (Sr) Atomic Number: 38 Mass: Four stable isotopes, ranging from 84 to 88 amu Laser cooling wavelength: Two different transitions are used in the laser cooling of strontium: a blue line at 461 nm that’s an ordinary sort of transition, and an exceptionally narrow “intercombination” line at 689 nm. Doppler cooling limit: 770…

Spooky Action at What Distance?

When I wrote up the giant interferometer experiment at Stanford, I noted that they’ve managed to create a situation where the wavefunction of the atoms passing through their interferometer contains two peaks separated by almost a centimeter and a half. This isn’t two clouds of atoms each definitely in a particular position, mind, this is…

A little over a year ago, I visited Mark Kasevich’s labs at Stanford, and wrote up a paper proposing to use a 10-m atom interferometer to test general relativity. Now, that sounds crazy, but I saw the actual tower when I visited, so it wasn’t complete nonsense. And this week, they have a new paper…

The last post in this series on the core technologies of cold-atom physics dealt with optical molasses, where you use the scattering of light to exert forces on atoms to make them very, very cold. It turns out, they end up even colder than the simple theory would lead you to expect, which is very…

The Making of a Sign Error

One thing I left out of the making-of story about the squeezed state BEC paper last week happened a while after publication– a few months to a year later. I don’t quite recall when it was– I vaguely think I was still at Yale, but I could be misremembering. It’s kind of amusing, in an…

I spend a lot of time promoting Rhett Allain’s Dot Physics blog, enough that some people probably wonder if I get a cut of his royalties (I don’t). I’m going to take issue with his latest, though, because he’s decided to revive his quixotic campaign against photons, or at least teaching about photons early in…