News & Highlights

Research Highlights

Freeze Frame
Published: 04-17-2010
The cold-molecule collaboration has developed a method for directly imaging ultracold ground-state KRb molecules. Their old method required the transfer of ultracold KRb molecules into a Feshbach state, which is sensitive to electric and magnetic fields. Thus researchers had to turn off the electric field and keep the magnetic field at a fixed value during the imaging process. However, the team recently began to probe the influence of changing electric and magnetic fields on the behavior of...
Good Vibrations
Published: 04-03-2010
Mathias Weber and his team recently did the following experiment: They excited the methyl group (CH3) on one end of nitromethane anion (CH3NO2-) with an infrared (IR) laser. The laser got the methyl group vibrating with enough energy to get the nitro group (NO2) at the other end of the molecule wagging hard enough to spit out its extra electron. The figure here, which appeared on the April 1, 2010, cover of the Journal of Physical Chemistry A, shows an artist’s conception of the process from...
The BEC Transporter
Published: 04-02-2010
The Dana Z. Anderson group has developed a microchip-based system that not only rapidly produces Bose-Einstein condensates (BECs), but also is compact and transportable. The complete working system easily fits on an average-sized rolling cart. This technology opens the door to using ultracold matter in gravity sensors, atomic clocks, inertial sensors, as well as in electric- and magnetic-field sensing. Research associate Dan Farkas demonstrated the new system at the American Physical Society’s...
Nanomeasurement is a Matter of the Utmost Precision
Published: 03-06-2010
Not content with stepping on their bathroom scales each morning to watch the arrow spin round to find their weights, former research associate John Teufel and Fellow Konrad Lehnert decided to build a nifty system that could measure more diminutive forces of half an attoNewton (0.5 x 10-18 N). Their new system consists of a tiny oscillating mechanical wire embedded in a microwave cavity with an integrated microwave interferometer, two amplifiers (one of them virtually noiseless), and a signal...
Radical Changes
Published: 02-24-2010
Carl Lineberger and his group recently achieved some exciting firsts: (1) the experimental observation of the oxyallyl diradical, a key intermediate in a series of important chemical reactions, and (2) the posting of an abstract of the Angewandte Chemie cover story reporting this achievement — on Facebook! While the Lineberger group is responsible for the clever design of the photoelectron spectroscopy experiments that led to the observation of oxyallyl diradical, Lineberger was astonished...
Buried Treasure
Published: 10-01-2009
The Anderson and Cornell groups have adapted two statistical techniques used in astronomical data processing to the analysis of images of ultracold atom gases. Image analysis is necessary for obtaining quantitative information about the behavior of an ultracold gas under different experimental conditions. Until now, the preferred method has been to find a shape (such as a Gaussian) that looks like the results and write an image-fitting routine to probe a series of photographs. The drawback is...
Extreme "Sheep" Herding
Published: 07-30-2009
The new molecules are as big as a virus. They’re ultracold. And, they’re held together by a ghostly quantum mechanical force field with the energy of about 100 billionths of an electron volt. These strange diatomic rubidium (Rb) molecules are the world’s first long-range Rydberg molecules. They were recently formed in Tilman Pfau’s laboratory at the University of Stuttgart from an ultracold cloud of Rb atoms. One neat aspect of the new experiment is that in 2000, Fellow Chris Greene’s...
Rave Reviews for the Efimov Quartet
Published: 07-15-2009
The most peculiar and fragile "molecules" ever discovered are the weakly bound triatomic Efimov molecules that form under specific conditions in a Bose-Einstein condensate (BEC). JILA theorists have now shown that such molecules can interact with an additional atom to form "daughter" molecules, which inherit many of their mother’s characteristics. What's strange is that the atoms in a BEC mostly feel no force of attraction to each other. In fact, the atoms only feel attracted to one...
Holy Monodromy!
Published: 07-02-2009
Monodromy literally means "once around." The term is applied in mathematics to systems that run around a singularity. In these systems, a parameter that describes the state of the system changes when the system loops around the singularity. Since monodromy’s discovery in 1980, mathematicians have predicted that many physical systems have it, including pendulums and tops as well as atoms and molecules. Fellow Heather Lewandowski’s group recently decided to do an experiment to see whether a...
A Light Changing Experience
Published: 04-29-2009
The Weber group wants to understand how the individual building blocks of DNA interact with ultraviolet (UV) light. Such knowledge would be an important step toward gaining a detailed understanding of the molecular processes responsible for the UV-induced DNA damage that results in mutations and can lead to cancer or cell death. Graduate student Jesse Marcum, student assistant Amit Halevi, and Fellow J. Mathias Weber recently studied the UV photodissociation of DNA subunits, called...
Free Association Tunes
Published: 04-14-2009
Starting with ultracold atoms in a Bose-Einstein condensate, it’s possible to create coherent superpositions of atoms and molecules. Fellow Carl Wieman and others have done exactly this. Recently, the Jin group wondered if it would be possible to accomplish the same thing starting with a normal gas cloud of atoms. To spice up the experiment, they included two kinds of atoms: neighborly bosons (87Rb) that readily pile up in the same state and more independent-minded fermions (40K), no two of...
Altered States
Published: 04-12-2009
Understanding how molecules collide is a hot topic in ultracold physics. Knowing the number of times molecules crash into each other and what happens when they do helps theorists predict the best ways to cool molecules to merely cold (1 K–1 mK), pretty cold (1 mK–1 µk), or ultracold ( Fellow John Bohn recently decided to investigate the general collision behavior of polar molecules in low-temperature gases. He wanted to see whether knowing the molecule’s dipole moment and mass would be...
It Takes Two to Tango
Published: 04-12-2009
Quantum dots are tiny structures made of semiconductor materials. With diameters of 1–5 nm, they are small enough to constrain their constituents in all three dimensions. This constraint means that when a photon of light knocks an electron into the conduction band and creates an electron/hole pair, the pair can’t get out of the dot. In terms of quantum mechanics, this confinement means that the wavelengths of the wave functions of both the electron and the hole are forced to be significantly...
How to Marry a Microscope
Published: 04-10-2009
The most important step for a microscope wanting to marry another microscope is finding the right partner. A professional matchmaker, such as the Perkins lab, might be just the ticket. The group recently presided over the nuptials of atomic force microscopy and optical-trapping microscopy. Research associate Gavin King, graduate students Ashley Carter and Allison Churnside, CU freshman Louisa Eberle, and Fellow Tom Perkins officiated. The marriage produced an ultrastable atomic force...
Fermions in Collision?
Published: 04-07-2009
According to the laws of quantum mechanics, identical fermions at very low temperatures can’t collide. These unfriendly subatomic particles, atoms, or molecules simply will not share the same piece of real estate with an identical twin. A few years back, researchers in the Ye lab considered this unneighborly behavior a big advantage in designing a new optical atomic clock based on an ensemble of identical 87Sr atoms. They (along with every other physicist in the world) assumed that using...
Collision Course
Published: 04-05-2009
The Greene group just figured out everything you theoretically might want to know about four fermions "crashing" into each other at low energies. Low energies in this context mean ultracold temperatures under conditions where large, floppy Feshbach molecules form. The group decided to investigate four fermions because this number makes up the smallest ultracold few-body system exhibiting behaviors characteristic of the transition between Bose-Einstein condensation and superfluidity. Senior...
Qubits in Action
Published: 04-05-2009
Fellows Ana Maria Rey and Jun Ye have come up with a clever idea that should make it much easier to design a quantum computer based on alkaline-earth atoms such as strontium (Sr). In this work, they collaborated with former research associate Marty Boyd, former JILA Fellow Peter Zoller (University of Innsbruck), and colleagues from Harvard University and the University of Innsbruck. To understand the new quantum computing idea, it’s helpful to imagine a high-tech company as a quantum...
Explosive Evidence
Published: 02-27-2009
Imagine being able to study how molecules form on the quantum level. It turns out that researchers have already figured out some nifty techniques involving lasers and jets of reactive atoms for doing just that in a gaseous environment. Now graduate student Alex Zolot, former Visiting Fellow Paul Dagdikian of Johns Hopkins University, and Fellow David Nesbitt have taken this kind of study into a whole different arena: They recently probed the molecules that form when the surface of a liquid is...
Beams In Collision
Published: 02-20-2009
Last year the Ye group conducted an actual laboratory astrophysics experiment. Graduate students Brian Sawyer, Ben Stuhl, and Mark Yeo, research associate Dajun Wang, and Fellow Jun Ye fired cold hydroxyl (OH) radicals into a linear decelerator equipped with an array of highly charged electrodes and slowed the OH molecules to a standstill. These molecules were then loaded into a permanent magnetic trap where they became the stationary target for collision studies. Next, Sawyer and his...
Breaking Up Is Hard To Do
Published: 02-13-2009
An oxygen molecule (O2) doesn't fall apart so easily — even when an X-ray knocks out one of its electrons and superexcites the molecule during a process called photoionization. In this process, the X-ray first removes an electron from deep inside the molecule, leaving a hole in O2+. Then, an outer electron can fall into the hole, and a second outer electron gets ejected, carrying away any excess energy. The loss of the second electron is known as autoionization, or Auger decay. Surprisingly, in...
Fortune’s Bubbles Rise and Fall
Published: 02-08-2009
A while back, former graduate student Scott Papp, graduate student Juan Pino, and Fellow Carl Wieman decided to see what would happen as they changed the magnetic field around a mixture of two different rubidium (Rb) isotopes during Bose-Einstein condensation. They assumed that the interactions between the atoms would change. They also expected they would observe two distinct condensates at some point. What they didn’t expect was the formation of alternating "bubbles" of 85Rb and 87Rb inside...
Exotic Probes
Published: 10-13-2008
Xibin Zhou and his colleagues in the Kapteyn/Murnane group have come up with a clever new way to study the structure of carbon dioxide (CO2) and other molecules. The researchers use two innovative tools: (1) coherent electrons knocked out of the CO2 molecules by a laser and (2) the X-rays produced by these electrons when they recollide with the same molecules. The coherent electrons and X-rays are produced in a process known as high harmonic generation. The process involves four steps. First,...
The Oldest Trick in the Book
Published: 10-03-2008
The mission to find the electron electric dipole moment (eEDM) recently took a menacing turn. Chief Eric Cornell and his protégés were already hard at work characterizing the hafnium fluoride ion (HfF+). Their goal was to be the first in the world to complete the mission. In their choice of molecule, they owed a lot to JILA theorists Ed Meyer and John Bohn (a.k.a. Agents 13 and 86), who had taken the theory world by storm in 2006 when they devised a simple and straightforward method for the...
All Quiet on the Amplifier Front
Published: 10-01-2008
Fellow Konrad Lehnert needed a virtually noiseless amplifier to help with his experiments on nanoscale structures, so he invented one. Working with graduate student Manuel Castellanos-Beltran and NIST scientists Kent Irwin, Gene Hilton, and Leila Vale, he conceived a tunable device that operates in frequencies ranging from 4 to 8 GHz. This device has the lowest system noise ever measured for an amplifier. In fact, it produces 80 times less noise than the best commercial amplifier. More...
From Mental to Experimental?
Published: 07-16-2008
The John Bohn lab at JILA owes its very existence to a 2002 decision by the Colorado Rockies to begin storing baseballs in a room with ~50% humidity. The conventional wisdom at the time was that Denver’s thinner air was responsible for making Coors Field a hitter’s heaven. In mile-high Denver, hitters averaged two more home runs per game because the thinner air caused a given home run ball to travel 20 feet further than at sea level. The humidified baseballs were supposed to solve the problem...

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