Experimental apparatus for the double-slit with a two-lobed laser mode.

Single Photons Are Still Photons: “Wave-particle dualism and complementarity unraveled by a different mode”

In which we do a little ResearchBlogging, taking a look at a slightly confusing paper putting a new twist on the double-slit experiment. ———— I’m off to California this afternoon, spending the rest of the week at DAMOP in Pasadena (not presenting this year, just hanging out to see the coolest new stuff in Atomic, […]

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 […]

Poll: Top Physics Story of 2010?

It’s the last week of the (calendar) year, which means it’s a good time to recap the previous twelve months worth of scientific news. Typically, publications like Physics World will publish a list of top ten physics stories of 2010, but we’re all Web 2.0 these days, so it seems more appropriate to put this […]

Teleportation of Toddler Toys

Today is the official release date for the paperback edition of How to Teach Physics to Your Dog, so I wanted to write up something cool about quantum physics to mark the occasion. I looked around the house for inspiration, and most of what we have lying around the house is SteelyKid’s toys. Thus, I […]

Interference of Independent Photon Beams: The Pfleegor-Mandel Experiment

Earlier this week, I talked about the technical requirements for taking a picture of an interference pattern from two independent lasers, and mentioned in passing that a 1967 experiment by Pfleegor and Mandel had already shown the interference effect. Their experiment was clever enough to deserve the ResearchBlogging Q&A treatment, though, so here we go: […]

Indirect Excitation Control: Ultrafast Quantum Gates for Single Atomic Qubits

Last week, John Baez posted a report on a seminar by Dzimitry Matsukevich on ion trap quantum information issues. In the middle of this, he writes: Once our molecular ions are cold, how can we get them into specific desired states? Use a mode locked pulsed laser to drive stimulated Raman transitions. Huh? As far […]

Bunches and Antibunches of Atoms: Hanbury Brown and Twiss Effects in Ultracold Atoms

Two papers in one post this time out. One of these was brought to my attention by Joerg Heber, the other I was reminded of when checking some information for last week’s mathematical post on photons. They fit extremely well together though, and both relate to the photon correlation stuff I was talking about last […]

Why Antibunching Equals Photons

In my post about how we know photons exist, I make reference to the famous Kimble, Dagenais, and Mandel experiment showing “anti-bunching” of photons emitted from an excited atom. They observed that the probability of recording a second detector “click” a very short time after the first was small. This is conclusive evidence that photons […]

Quantum Optics from the Opposite Direction: QED Limits on Laser Intensities

Most of the time, when we talk about seeing quantum effects from light, we talk about extremely weak beams– looking at intensities where one photon more or less represents a significant change in the intensity of the light. Last week, though, Physics Buzz wrote up a paper that goes in the other direction: they suggest […]

What’s a Photon, and How Do We Know they Exist?

A reader emailed me with a few questions regarding How to Teach Physics to Your Dog, one of which is too good not to turn into a blog post: What is a photon from an experimental perspective?… Could you perhaps provide me with a reference that discusses some experiments and these definitional issues? The short […]