News & Highlights

Research Highlights

The South Broadway Shootout
Published: 10-01-2006
In the race to develop the world's best optical atomic clock, accuracy and precision are what count. Accuracy is the degree to which a measurement of time conforms to time's true value. Precision is a gauge of the exactness, or reproducibility, of the measurements. By definition, a high-precision clock must be extremely stable. JILA may well be home to one of the world's most precise (and stable) optical atomic clocks, thanks to the efforts of graduate students Marty Boyd, Andrew Ludlow, Seth...
Bull's Eye!
Published: 07-28-2006
"Chemistry is a highly improbable science," says Graduate Student Mike Deskevich, who adds "It's good for life on Earth that things are so unreactive." For instance, if chemical reactions happened easily and often, oxygen in the air would cause clothing and other flammable materials to burst into flame. In addition to making life difficult, high probability chemistry would render theoretical chemical physics much less interesting. As it is, theorists spend months determining the particular...
Spectral Shapes
Published: 07-17-2006
The breakdown of chlorofluorocarbons (CFCs) in the stratosphere has been implicated in the destruction of Earth's protective ozone layer. Consequently, scientists have undertaken studies to better understand the structure and behavior of highly reactive, but short-lived, free radicals produced during the breakdown process. The molecules, which contain either fluorine or chlorine, are an important source of atmospheric halogen atoms. Elucidating their 3D structure and dynamical behavior will...
Trapped!
Published: 07-16-2006
A solvent is something that dissolves or disperses something else. It's the water in salt water, the alcohol in cough syrup, the lactates or ethers in inks. For many of us, solvents are the background music of the chemistry taking place all around us. But this isn't how Fellow Carl Lineberger and his colleagues in chemical physics think about solvents. Lineberger, Former Research Associate Vladimir Dribinski, Graduate Students Jack Barbera and Josh Martin, and student visitor Annette Svendsen...
Gold Fever
Published: 07-07-2006
Life can be challenging on the biophysics research frontier. Consider gold nanoparticles as a research tool, for example. Gold is ductile and malleable as well as being a good conductor of heat and electricity. Its unique chemistry allows proteins and DNA to be easily attached to these nanoparticles. Physicists have been investigating gold nanoparticles in optical-trapping experiments because they enhance trapping efficiency and potentially increase detection sensitivity. Medical scientists...
Constant Vigilance
Published: 07-03-2006
The fine structure constant is getting a lot of attention these days. Known as α, it is the "coupling constant," or measure of the strength of the electromagnetic force that governs how electrons, muons, and light interact. What's intriguing is that new models for the basic structure of matter predict that α may have changed over vast spans of cosmic time, with the largest variations occurring in the early universe. However, the Standard Model says a has always been the same. Our basic...
Flashdance!
Published: 06-07-2006
Imagine trying to describe the intricate motions of a single atom as it interacts with a laser. Then suppose you could generalize this understanding to a whole cloud of similar atoms and predict the temperatures your experimental physicist colleagues could achieve with laser cooling. This way-cool theoretical analysis comes compliments of Graduate Student Josh Dunn and Fellow Chris Greene. The researchers have completed a detailed calculation of atom-light interactions, which they use to treat...
Heme Motions
Published: 05-17-2006
Our lives depend on heme. As part of hemoglobin, it carries oxygen to our tissues. As part of cytochrome c, it helps transform the energy in food into the energy-rich molecule ATP (adenosine triphosphate) that powers biochemical reactions that keep us alive and moving. As part of cytochrome P450, it helps break down toxic chemicals in our bodies. What is this thing called heme? And, how does it do such amazing work inside our bodies? Scientists know that heme is a large ringed molecule...
Charting the Fermi Sea
Published: 04-03-2006
JILA physicists are collaborating to explore the link between superconductivity and Bose-Einstein condensation (BEC) of fermions at ultracold temperatures. Fermions have an odd number of total protons, neutrons, and electrons, giving them a half integer spin, which is either up or down. At ultracold temperatures, this means fermions can't just occupy the same energy level (like bosons, which have an even number of atomic constituents) and form one superatom in a BEC. Instead, they stack up in...
Cracking the Collision Code
Published: 02-25-2006
When molecules smash into each other, things happen on the quantum level. Electrons get shoved around. They may even jump from one atom to another. Spin directions can change. A chemical reaction may even take place. Since it's not possible to directly observe this kind of electron behavior, scientists want to be able to probe it with novel spectroscopies. Now, thanks to a recent theoretical study, ultracold spectroscopy looks particularly promising for elucidating electron behavior during...
Designer Rings
Published: 02-11-2006
One way to understand unstable molecules is to systematically create slightly different versions of a similar stable molecule and investigate each new molecule with identical analysis and experiments. That is exactly what researchers from JILA and CU are doing with a series of ringed molecules. The JILA researchers are Graduate Student Adam Gianola, Postdoctoral Research Associate Takatoshi Ichino, and Fellow Carl Lineberger. Their CU collaborators are Lecturer Rebecca Hoenigman, Senior...
Physics Class Rocks!
Published: 10-01-2005
Imagine high-school or college students so excited about physics they can hardly wait to get to class every day and learn more about how the world works. Fellow Carl Wieman recently offered cogent suggestions to new physics teachers on coming closer to this ideal. First, he recommended starting with research on how people learn physics and paying particular attention to the concept of "cognitive load." This concept, which posits that people can only process about seven ideas in short-term...
Measure the Force, Luke
Published: 10-01-2005
Graduate students Dave Harber and John Obrecht, postdoc Jeff McGuirk, and Fellow Eric Cornell recently devised a clever way to use a Bose-Einstein condensate (BEC) inside a magnetic trap to probe the quantum behavior of free space. To do this, the researchers first created a BEC inside a magnetic trap, whose shape (where the condensate forms) resembles a cereal bowl. Then as shown in the diagram to the right, they moved the BEC in the bowl closer and closer to a glass surface until...

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