Category: Cold Atoms

Tiny Forces, Artificial Materials, and Wobbling Stars: Physics Post Round-Up

I’ve been really busy with year-end wrap-up stuff, but have also posted a bunch of stuff at Forbes. which I’ve fallen down on my obligation to promote here… So, somewhat belatedly, here’s a collection of physics-y stuff that I’ve written recently: — Using Atoms To Measure Tiny Forces: A post reporting on some very cool… Continue reading Tiny Forces, Artificial Materials, and Wobbling Stars: Physics Post Round-Up

How Not to Control the Weather for Your Dog

Emmy, the Queen of Niskayuna, sitting in the snow hoping the camera will spit out some treats.

I’m rooting around in my bag for a pen, and pull out a laser pointer by mistake. Since I’d really prefer not to be grading, I flip it on and shine it on the floor next to the spot where Emmy is half-dozing. She immediately leaps up (she’s pretty spry for a dog of 12…),… Continue reading How Not to Control the Weather for Your Dog

Super Bowl Athletes Are Scientists At Work

I wrote up another piece about football for the Conversation, this time drawing on material from Eureka, explaining how great football players are using scientific thinking: Seattle Seahawks cornerback Richard Sherman gets called a lot of things. He calls himself the greatest cornerback in the NFL (and Seattle fans tend to agree). Sportswriters and some… Continue reading Super Bowl Athletes Are Scientists At Work

Small College, Exotic Particles

Topping the looooong list of things I would give a full ResearchBlogging write-up if I had time is this new paper on a ultra-cold atom realization of “Dirac Monopoles”. This is really cool stuff, but there are a lot of intricacies that I don’t fully understand, so writing it up isn’t a simple matter. The… Continue reading Small College, Exotic Particles

Laser-Cooled Atoms: Ytterbium

Ytterbium metal, and artsy shot of a Yb MOT at JQI, and an electron shell diagram.

Element: Ytterbium (Yb) Atomic Number: 70 Mass: Seven “stable” isotopes, from 168 to 176 amu. Two of those are nominally radioactive, with half-lives vastly in excess of the age of the universe. Laser cooling wavelength: 399 nm and 556 nm. Doppler cooling limit: 690 μK in the UV and 4.4 μK in the green. Chemical… Continue reading Laser-Cooled Atoms: Ytterbium

Laser-Cooled Atoms: Cesium

L to R, cesium metal in a glass ampule, a college classmate working on a cesium cooling apparatus at Stanford, and an electron shell diagram.

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… Continue reading Laser-Cooled Atoms: Cesium

Laser-Cooled Atoms: Chromium

L to R: Shiny chromium bits, laser tables for the chromium trap in Paris, and an electron shell diagram.

Element: Chromium (Cr) Atomic Number: 24 Mass: Four “stable” isotopes between 50 and 54 amu. Chromium-50 is technically radioactive, with a half-life considerably longer than the age of the universe, so… Laser cooling wavelength: 425nm, but see below. Doppler cooling limit: 120 μK. Chemical classification: Transition metal, smack in the middle of the periodic table.… Continue reading Laser-Cooled Atoms: Chromium

Laser-Cooled Atoms: Lithium

L to R, lithium metal in paraffin, the red light for cooling lithium (from the LaserFest web site), and an electron shell diagram from wikimedia.

Element: Lithium (Li) Atomic Number: 3 Mass: Two stable isotopes, masses 6 and 7 amu Laser cooling wavelength: 671 nm Doppler cooling limit: 140 μK. Chemical classification: Alkali metal, column I in the periodic table. Yet another greyish metal. We’re almost done with alkalis, I promise. Less reactive than any of the others, so the… Continue reading Laser-Cooled Atoms: Lithium

Laser-Cooled Atoms: Francium

L to R, a schematic of the accelerator used to make francium, a cartoons of a system with an anapole moment (both take from the William and Mary group), and an electron shell diagram for francium from Wikimedia.

Element: Francium (Fr) Atomic Number: 87 Mass: Numerous isotopes ranging in mass from 199 amu to 232 amu, none of them stable. The only ones laser cooled are the five between 208 amu and 212 amu, plus the one at 221 amu. Laser cooling wavelength: 718 nm Doppler cooling limit: 182 μK. Chemical classification: Alkali… Continue reading Laser-Cooled Atoms: Francium