Research Highlights

  • Everything is Illuminated
    August 15, 2011
    PI(s): Richard McCray
    Topic(s): Astrophysics

    Supernova 1987A is illuminating its own past. The brightest supernova to light up Earth’s night skies since the Renaissance, it appeared in the southern sky on February 23, 1987 when a blue supergiant star exploded in the Large Magellanic Cloud, a galaxy located 160,000 light years from Earth. For nearly 25 years, Fellow Dick McCray and his colleagues have studied the unfolding story of this remarkable event in the visible, ultraviolet, and x-ray wavelengths. Today, the scientists not only understand the star’s spectacular demise, but also are now learning about the blue supergiant’s chemistry prior to going supernova.

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  • Reactions on Demand
    July 16, 2011
    PI(s): Henry Kapteyn, Margaret Murnane
    Topic(s): Laser Physics

    Predrag Ranitovic dreams of controlling chemical reactions with ultrafast lasers. Now he and his colleagues in the Kapteyn/Murnane group are one step closer to bringing this dream into reality. The group recently used a femtosecond infrared (IR) laser and two extreme ultraviolet (XUV) harmonics created by the same laser to either ionize helium atoms or prevent ionization, depending on experimental conditions. The researchers adjusted experimental conditions to manipulate the electronic structure of the helium atoms as well as control the phase and amplitude of the XUV laser pulses.

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  • The Secrets of the Resonant Lattice
    July 15, 2011
    PI(s): Ana Maria Rey
    Topic(s): Atomic & Molecular Physics

    Theoretical physicists recently combined two powerful tools for exploring ultracold atomic gases: Optical lattices and Feshbach resonances. Optical lattices are crystals of light formed by interacting laser beams. Feshbach resonances in an ultracold atom gas occur at a particular magnetic field strength and cause ultracold atoms to form very large, loosely associated molecules. However, because lattice atoms interact strongly at a Feshbach resonance, the physics of Feshbach resonances in an optical lattice is quite complicated.

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  • Quantum CT Scans
    June 01, 2011
    PI(s): Konrad Lehnert
    Topic(s): Nanoscience, Precision Measurement

    The Lehnert group and collaborators from the National Institute of Standards and Technology (NIST) recently made what was essentially a CT scan of the quantum state of a microwave field. The researchers made 100 measurements at different angles of this quantum state as it was wiggling around. Because they only viewed the quantum state from one angle at a time, they were able to circumvent quantum uncertainties to make virtually noiseless measurements of amplitude changes in their tiny microwave signals. Multiple precision measurements of the same quantum state yielded a full quantum picture of the microwave field.

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  • JILA MONSTR and the Chamber of Secrets
    May 17, 2011
    PI(s): Steven Cundiff
    Topic(s): Nanoscience

    The semiconductor gallium arsenide (GaAs) is used to make tiny structures in electronic devices such as integrated circuits, light-emitting diodes, laser diodes, and solar cells that directly convert light into electrical energy. Because of GaAs’s importance to modern electronics, the Cundiff group seeks to understand the fundamental physics of its light-matter interactions on atomic and electronic levels.

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  • I Sing the Body Electric
    May 11, 2011
    PI(s): Heather Lewandowski
    Topic(s): Chemical Physics

    The Lewandowski group recently decided to see what would happen if it could get cold molecules (1K–1mK) and ultracold (<1mK) atoms to collide. Former graduate student L. Paul Parazzoli, graduate student Noah Fitch, and Fellow Heather Lewandowski devised a novel experiment to determine the collision behavior of cold (100 mK) deuterated ammonia (ND3) molecules and ultracold (600 microK) rubidium (Rb) atoms.

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  • A Flair for Lasing
    May 01, 2011
    PI(s): Chris Greene
    Topic(s): Atomic & Molecular Physics

    Triatomic hydrogen ion (H3+) has many talents. In interstellar clouds, it can be blown apart by free low-energy free electrons, which interact with the ion core (H3+), briefly forming unstable H3 molecules. The interaction of the electron with the ion core almost immediately causes the molecule to fall apart into three hydrogen atoms (3H) or a hydrogen molecule (H2) and an H atom. This reaction is known as dissociative recombination.

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  • Upending Conventional Wisdom
    April 21, 2011
    PI(s): Thomas Perkins
    Topic(s): Biophysics

    In science, it can be fun and interesting to upend conventional wisdom. A good example is what just happened to a widely accepted explanation for overstretching of double-stranded DNA (dsDNA). Overstretching occurs suddenly when researchers add a tiny increment of force to dsDNA that is already experiencing a pulling force of approximately 65 pN. (A piconewton is a trillionth of a newton, which is roughly equal to the gravitational force on a medium-sized apple). The small additional force causes the dsDNA to suddenly become 70% longer — as it stretches like a slinky.

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  • The World According to COS
    April 20, 2011
    PI(s): Jeffrey Linsky
    Topic(s): Astrophysics

    The Cosmic Origins Spectrograph, or COS, is a powerful new instrument scanning the Universe. COS was installed on the Hubble Space Telescope in 2009. Since then, it has been searching for clues about the composition of the Universe, including how galaxies like our own Milky Way formed and evolved over time. It is seeing beautiful things never before detected in the Universe because it is the lowest-noise ultraviolet (UV) spectrograph ever built for space exploration.

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  • The Long Goodbye
    April 02, 2011
    PI(s): Andreas Becker
    Topic(s): Chemical Physics

    The dance of electrons as a bromine molecule (Br2) separates into two atoms is intricate and complex. The process of breaking up takes far longer than expected (~150 vs 85 fs) because the cloud of electrons that bind atoms together in a molecule behaves as if it were still surrounding a molecule until the last possible moment — when the atomic fragments are about twice the normal distance apart (~.55 nm). At this point, there’s simply not enough energy left in the system to hold the molecule together. When the two atoms finally appear as separate entities, it was if someone had snapped a rubber band.

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  • The Quantum Control Room
    March 21, 2011
    PI(s): Deborah Jin, John Bohn, Jun Ye
    Topic(s): Quantum Information Science & Technology

    In 2008, the Ye and Jin groups succeeded in making ultracold potassium-rubidium (KRb) molecules in their ground state (See “Redefining Chemistry at JILA” in the Spring 2010 issue of JILA Light & Matter). Their next goal was to figure out how to precisely control chemical reactions of these ultracold polar molecules by manipulating the quantum states of the reactants. But first the researchers had to discover how to calm those reactions down enough to study them. Under the conditions in which they were made (an optical trap allowing motion in all three dimensions), ultracold KRb molecules were so chemically reactive they disappeared almost as soon as they were formed.

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  • The Fickle Finger of Fate
    February 24, 2011
    PI(s): John Bohn
    Topic(s): Atomic & Molecular Physics

    Putting the brakes on a superfluid dipolar Bose-Einstein condensate (BEC) just got a whole lot more interesting. Last year, the Bohn theory group explored what would occur in a dipolar BEC when a laser probe — think of it like a finger — tickled a BEC just hard enough to excite a roton.

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  • Strontium Clock Performance Skyrockets
    February 03, 2011
    PI(s): Ana Maria Rey, Jun Ye
    Topic(s): Precision Measurement

    In 2008-2009, much to their amazement,researchers working on the Jun Ye group’s neutral Sr optical atomic clock discovered tiny frequency shifts caused by colliding fermions! They figured out that the clock laser was interacting slightly differently with the Sr atoms inside a one-dimensional (pancake-shaped) trap. The light-atom interactions resulted in the atoms no longer being identical. And, once they were distinguishable, formerly unneighborly atoms were able to run into each other, compromising clock performance.

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  • Puff the Magic Planet
    January 21, 2011
    PI(s): Rosalba Perna
    Topic(s): Astrophysics

    Hot Jupiters — giant gas planets orbiting close to their parent stars — aren’t just scorched (at temperatures of >1000 K). They are also swollen up larger than can be explained by the intense heat from their host stars. Recently Fellow Rosalba Perna and her colleagues from Columbia University and the Kavli Institute for Theoretical Physics suggested a reason why these planets are so puffed up: The swelling results from heat dissipated from electric currents generated by the interaction of robust magnetic fields (generated from deep within the giant planets) with strong atmospheric winds carrying charged particles called ions.

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  • The Quantum Modeling Agency
    January 14, 2011
    PI(s): Ana Maria Rey, Jun Ye
    Topic(s): Quantum Information Science & Technology

    “Nature is built quantum mechanically,” says Fellow Jun Ye, who wants to understand the connections between atoms and molecules in complex systems such as liquids and solids (aka condensed matter). He says that the whole Universe is made of countless interacting particles, and it would be impossible to figure out the myriad connections between them one particle at a time, either theoretically or experimentally.

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  • The Incredible Solar Bread Machine
    January 04, 2011
    PI(s): Alan Gallagher
    Topic(s):

    After he retired, Fellow Alan Gallagher decided to take his interest in solar energy in a whole new direction: He decided to design, build, and test a unique large-area frying pan heated by the Sun’s energy. The new solar frying pan was specifically tailored to the cooking of injera bread in East Africa.For more than 100 million people in East Africa, the thin, flexible, and pancakelike bread is a mainstay of their diet. It is usually eaten with a variety of thick sauces spread around the top of a large (~0.4 m diameter) slice, which serves as a shared “dinner plate.” 

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  • Sharing the Adventure of Science
    January 04, 2011
    PI(s): Eric Cornell
    Topic(s): Other

    Graduate students or research associates at JILA have the option of signing up to help teach after-school science classes to elementary and middle school students in the St. Vrain School District. The volunteers expect to stimulate the children to learn to think critically, enjoy science activities, and become confident in their own abilities to master difficult concepts. What they may not anticipate at first is that they will learn some important skills themselves, including the ability to communicate scientific concepts in everyday language and, with that new ability, gain a better understanding of education.

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  • Seeds of Creation: Monster Stars or Quasistars?
    December 29, 2010
    PI(s): Mitch Begelman
    Topic(s): Astrophysics

    There are two competing ideas about the origin of the monster black holes at the center of galaxies. Both include exceptional stars that have never actually been observed: (1) massive population III (Pop III) stars (as big as a thousand Suns) made of pure hydrogen and helium that would have formed less than 100 million years after the Big Bang, and (2) gigantic quasistars whose shining envelopes were powered, not by nuclear fusion, but by energy emitted by the black holes inside them.

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  • Ionize Me!
    December 20, 2010
    PI(s): Andreas Becker
    Topic(s): Atomic & Molecular Physics

    Plucking the two electrons out of helium atoms should allow researchers to study how they interact during a double ionization process — at least in theory. Recently, Fellow Andreas Becker explored whether an ultrashort vacuum ultraviolet (VUV) laser pulse could be used to probe the interactions of helium’s electrons during a double ionization in the presence of an intense infrared (IR) laser field.

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  • Big G isn't the problem: Measuring it is!
    December 20, 2010
    PI(s): James Faller
    Topic(s): Precision Measurement

    Of all the fundamental forces, gravity is the most difficult to precisely measure. This difficulty is reflected in how hard it is to accurately measure “Big G,” a fundamental constant that is part of the measurement of the gravitational force. In fact, big G is the least precisely measured fundamental constant in physics. Who would have imagined that the very first fundamental force to be discovered would still be somewhat mysterious more than 300 years later? Or, that a force most of us take for granted in everyday life is actually very hard to precisely measure?

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  • Rainbows of Soft X-Rays
    December 06, 2010
    PI(s): Henry Kapteyn, Margaret Murnane
    Topic(s): Laser Physics

    The vision of a tabletop x-ray laser has taken a giant step into reality, thanks to Tenio Popmintchev, Ming-Chang Chen and their colleagues in the Kapteyn/Murnane group. By focusing a femtosecond laser into a gas, Popmintchev and Chen generated many colors of x-rays at once, in a band that stretched from the extreme ultraviolet into the soft x-ray region of the electromagnetic spectrum, spanning wavelengths of ranging from about 6 to 2.5 nm. This broad x-ray band has so many different colors that all the waves can be added together to form the shortest strobe light in existence.

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  • Sayonara Demolition Man
    November 30, 2010
    PI(s): James Thompson
    Topic(s): Atomic & Molecular Physics, Precision Measurement

    The secret for reducing quantum noise in a precision measurement of spins in a collection of a million atoms is simple: Pre-measure the quantum noise, then subtract it out at the end of the precision measurement. The catch is not to do anything that detects and measures the spins of individual atoms in the ensemble. If states of individual atoms are measured, then those atoms stop being in a superposition and the subsequent precision measurement will be ruined.

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  • Deciphering Nature's Fingerprints
    November 24, 2010
    PI(s): Jun Ye
    Topic(s): Atomic & Molecular Physics

    Fellow Jun Ye’s group has enhanced the molecular fingerprinting technique with the development of a mid-infrared (mid-IR) frequency comb.  The new rapid-detection technique can now identify traces of a wider variety of molecules found in mixtures of gases. It offers many advantages for chemical analysis of the atmosphere, climate science studies, and the detection of suspicious substances.

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  • The Guiding Light
    November 24, 2010
    PI(s): Thomas Perkins
    Topic(s): Biophysics

    Atomic force microscopy (AFM) just got a whole lot more efficient for studying proteins and other biomolecules. Graduate student Allison Churnside, former research associate Gavin King, and Fellow Tom Perkins recently used a laser to detect the position of sparsely distributed biomolecules on a glass cover slip. Since the same laser is also used to locate the AFM tip, it is now possible to align the microscope tip and sample with a precision of 40 nm, before the AFM tip even touches the sample. The researchers say that the new sample detection scheme solves the “needle in a haystack” problem of nanoscale microscopy.

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  • In the Beginning
    October 02, 2010
    PI(s): Mitch Begelman
    Topic(s): Astrophysics

    Before there were galaxies with black holes in their centers, there were vast reservoirs of dark matter coupled to ordinary matter, mostly hydrogen gas. These reservoirs were sprinkled with the Universe’s early stars born in pregalactic dark matter halos. But according to Fellow Mitch Begelman, another population of atypical stars formed millions of years later during the creation of galaxies. These stars grew to truly colossal sizes — a million times more massive than the Sun.

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  • Canned Heat
    August 18, 2010
    PI(s): Eric Cornell
    Topic(s): Other

    A while back, Fellow Eric Cornell started thinking about all the waste heat produced by the use of water to cool refi neries and other industrial plants. In a few places, the waste hot water — at ~212°F — is used to heat commercial and apartment buildings. 

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  • Sizzling Planet Sports Cometlike Tail
    August 18, 2010
    PI(s): Jeffrey Linsky
    Topic(s): Astrophysics

    A faint star that can easily be seen from Earth with binoculars has a Jupiter-like gas planet orbiting it once in just three days. That means the planet is close enough to its Sun-like star to get scorching hot, which affects both the planet and its atmosphere. The star is called HD209458, and its planet’s moniker is HD209458b.

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  • An Occurence at the Solvent Bridge
    August 18, 2010
    PI(s): W. Carl Lineberger
    Topic(s): Chemical Physics

    Solvents don’t just dissolve other chemicals (called solutes) and then sit around with their hands in their pockets. Instead, they get involved in all sorts of different ways when dissolved molecules toss electrons around, i.e., they facilitate charge transfer events. In research, the hard part is fi guring out exactly how and when solvent molecules get involved when an electron hops from one solute molecule to another. For example, in liquids (which do most of the dissolving), solvent molecules move constantly, making it very challenging to see what they’re doing when charge transfer events occur.

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  • Curling Up in a Nanobathtub
    August 18, 2010
    PI(s): David Nesbitt
    Topic(s): Nanoscience

    In microscopic studies of single biological molecules or nanoparticles, it’s useful to be able to precisely control the temperature around the sample. Until now, heating has required electric currents that warm up microscope stages, slides, and optics in addition to the specimen under study. Such methods are slow and hard to control, not to mention capable of accidentally altering the chemistry or structure of the sample. Now there is a better solution for keeping samples nice and warm: The nanobathtub.

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  • Window into the Sun
    August 18, 2010
    PI(s): Juri Toomre
    Topic(s): Astrophysics

    Senior research associate Brad Hindman of the Toomre group uses helioseismology to understand what’s happening under the surface of the Sun. Helioseismology is a lot like the ultrasound tests used to evaluate medical conditions. However, there’s a big difference: physicians already have a good idea of the basic structures they are probing with sound waves. Helioseismologists don’t. They study sound that travels below the Sun’s surface to learn about the structure and behavior of the Sun’s convection zone, which comprises the outer third of the Sun. However, if they misinterpret the nature of the sounds they analyze, then they are likely to miss the mark in determining what’s happening inside the Sun.

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  • Gone to the Dark Side, It Has
    August 18, 2010
    PI(s): Steven Cundiff
    Topic(s): Atomic & Molecular Physics

    When former graduate student Mingming Feng started his thesis project, his goal was to build and characterize a mode-locked quantum dot diode laser in Kevin Silverman’s lab at the National Institute of Standards and Technology (NIST).

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  • The Mysterious Fermi Gap
    August 18, 2010
    PI(s): Deborah Jin
    Topic(s): Atomic & Molecular Physics

    In 2008, the Deborah Jin Group introduced a new technique, known as atom photoemission spectroscopy, to study a strongly interacting ultracold gas cloud of potassium (40K) atoms at the crossover point between Bose-Einstein condensation and superfl uidity via the pairing of fermionic atoms (See JILA Light & Matter, Summer 2008). Near the crossover point, the physics of superfl uidity in an atom gas system may be connected to that of high-temperature superconductivity.

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  • Them's the Brakes
    August 18, 2010
    PI(s): John Bohn
    Topic(s): Atomic & Molecular Physics

    The Bohn group has just come up with an exciting, really complicated experiment for someone else to do. This is something theorists like graduate student Ryan Wilson, former research associate Shai Ronen, and Fellow John Bohn get a kick out of. In this case, they’re recommending an experiment to measure how fast a tiny blue laser would have to move through a dipolar Bose-Einstein condensate (BEC) to create ripples.

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  • Molecular Motion Pictures
    July 06, 2010
    PI(s): Chris Greene, Henry Kapteyn, Margaret Murnane
    Topic(s): Atomic & Molecular Physics

    If you want to understand how chemical reactions happen, the ability to monitor dynamic positions of atoms in a molecule is critical. There's a well-known laser technique known as coherent Raman spectroscopy that uses a scattering laser pulse to set atoms vibrating and then measures the color shift of reflected light to detect vibration patterns. This technique has been used as a molecular fingerprinting device for simple motions of a molecule.

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  • Redefining Chemistry at JILA
    May 06, 2010
    PI(s): Deborah Jin, Jun Ye, Konrad Lehnert
    Topic(s): Atomic & Molecular Physics

    Fellows Deborah Jin, Jun Ye, and John Bohn are exploring new scientific territory in cold-molecule chemistry. Experimentalists Jin and Ye and their colleagues can now manipulate, observe, and control ultralow-temperature potassium-rubidium (KRb) molecules in their lowest quantum-mechanical state. Theorist Bohn analyzes what the experimentalists see and predicts molecule behaviors under different conditions.

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  • Freeze Frame
    April 17, 2010
    PI(s): Deborah Jin, Jun Ye
    Topic(s): Atomic & Molecular Physics

    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.

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  • Close Encounters of the Third Dimension
    April 10, 2010
    PI(s): Henry Kapteyn, Margaret Murnane
    Topic(s): Atomic & Molecular Physics

    When Richard Sandberg and his colleagues in the Kapteyn/Murnane group developed a lensless x-ray microscope in 2007 (see JILA Light & Matter, Winter 2008), they were delighted with their ability to obtain a stick-figure image (below) that was comparable in resolution to one from a scanning-electron microscope. 

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  • Sculpting a Star System: The Outer Planets
    April 10, 2010
    PI(s): Phil Armitage
    Topic(s): Astrophysics

    Fellow Phil Armitage and colleagues from the Université de Bordeaux and Google, Inc. are key players in the quest to understand the secrets of planet formation. Current theory posits that there are three zones of planet formation around a star (as shown in the figure). In Zone One, the hot innermost zone, small rocky planets form over a period of hundreds of millions of years. The planets form too slowly to accrete gas from the original planetary disk. Zone One is the terrestrial, or habitable, zone.

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  • The Magnetic Heart of the Matter
    April 05, 2010
    PI(s): Henry Kapteyn, Margaret Murnane
    Topic(s): Atomic & Molecular Physics

    Imagine being able to observe how a magnet works at the nanoscale level, both in space and in time. For instance, how fast does a nanoscale magnetic material switch its orientation? What if understanding magnetic switching might lead to the use of the spin of an electron rather than its charge to create new devices? A new method for investigating such possibilities is just beginning to be explored.

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  • Good Vibrations
    April 03, 2010
    PI(s): J. Mathias Weber
    Topic(s): Chemical Physics

    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.

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  • The BEC Transporter
    April 02, 2010
    PI(s): Dana Anderson
    Topic(s): Atomic & Molecular Physics, Precision Measurement

    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 March 2010 meeting, held in Portland, Oregon, March 15–19, 2010.

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  • The Great Migration
    March 09, 2010
    PI(s): Phil Armitage
    Topic(s): Astrophysics

    Fellow Phil Armitage studies the migration of gas giant planets through evolving protoplanetary disks. He and former JILA postdoc Richard Alexander (Universiteit Leiden) have designed relatively simple models that reproduce the observed frequency and distribution of extra-solar giant planets, many of which orbit very close to their stars. The models also replicate the masses, lifetimes, and evolution of protoplanetary disks.

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  • Nanomeasurement is a Matter of the Utmost Precision
    March 06, 2010
    PI(s): Konrad Lehnert
    Topic(s): Precision Measurement

    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 detector.

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  • Radical Changes
    February 24, 2010
    PI(s): W. Carl Lineberger
    Topic(s): Chemical Physics

    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 that his work got on Facebook. He speculated that the journal’s publisher, Wiley-VCH, was responsible.

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  • First Light
    February 10, 2010
    PI(s): Peter Bender, Phil Armitage
    Topic(s): Astrophysics

    The merger of supermassive black holes is a hot topic in astrophysics. Such mergers may occur after the formation of black hole binaries during galaxy collisions. The mergers are predicted to emit gravitational waves, whose detection is the mission of the Laser Interferometer Space Antenna (LISA). In preparation for the LISA mission, which is scheduled for launch in 2018, Fellow Peter Bender is working with colleagues around the world to improve LISA’s design (see JILA Light & Matter, Summer 2006).

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  • Ballistic Evidence
    February 10, 2010
    PI(s): Henry Kapteyn, Margaret Murnane
    Topic(s): Nanoscience

    Heat does not always flow as rapidly near nanostructures as it typically does in solids. Instead, it can go ballistic! Ballistic heat transfer occurs near a tiny device if its size is smaller than the distance a phonon, or lattice vibration, travels before colliding with another phonon. When this happens, heat flow is reduced, and a nanoscale hot spot is created. Ballistic heat transfer away from a hot spot can be as much as three times less efficient than ordinary heat diffusion.

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  • Stretched Thin
    February 08, 2010
    PI(s): Ralph Jimenez
    Topic(s): Biophysics, Chemical Physics

    Fellow Ralph Jimenez is applying his knowledge of lasers, microscopy, and the precise control of tiny amounts of fluids to the development of a battery-powered blood analyzer for use "off-grid" in Third World countries. He is collaborating with Jeff Squier, David Marr, and their students from the Colorado School of Mines and Charles Eggleton and his student from the University of Maryland, Baltimore County, to see if they can come up with a fast and accurate way to measure the elasticity, or stiffness, of individual red blood cells as they flow through an "optical lab on a chip."

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  • The Coldest Horse in the Race
    January 31, 2010
    PI(s): John Bohn
    Topic(s): Atomic & Molecular Physics, Precision Measurement

    The race to measure the electron’s electric dipole moment (eEDM) is picking up speed across the world, thanks to graduate student Ed Meyer of JILA’s Lazy Bohn’s Ranch (i.e., John Bohn’s theory group). Meyer has identified more than a dozen horses, a.k.a. molecules and molecular ions, with strong enough internal electric fields to compete in the eEDM derby. Imperial College of London’s Ed Hinds is riding YbF (ytterbium fluoride) and leads by a nose.

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  • Crafting Star Systems like Our Own
    October 03, 2009
    PI(s): Phil Armitage
    Topic(s): Astrophysics

    Most known extrasolar planetary systems comprise planets whose orbits vary wildly from the nearly circular ellipses found in our solar system. This wide variation in eccentricity is thought to occur when large gas planets interact with each other, causing gyrations in planetary orbits, planet migrations toward and away from the central star, and even the ejections of planets out of the star system. 

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  • Buried Treasure
    October 02, 2009
    PI(s): Dana Anderson, Eric Cornell
    Topic(s): Atomic & Molecular Physics, Precision Measurement

    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. 

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  • Fermions in Collision?
    September 07, 2009
    PI(s): Jun Ye
    Topic(s): Precision Measurement

    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. 

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  • Fortune’s Bubbles Rise and Fall
    August 02, 2009
    PI(s):
    Topic(s): Atomic & Molecular Physics

    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.

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  • Extreme "Sheep" Herding
    July 30, 2009
    PI(s): Chris Greene
    Topic(s): Atomic & Molecular Physics

    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. 

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  • Rave Reviews for the Efimov Quartet
    July 15, 2009
    PI(s): Chris Greene
    Topic(s): Atomic & Molecular Physics

    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.

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  • Cloud Tripping Through the Milky Way
    July 13, 2009
    PI(s): Jeffrey Linsky
    Topic(s): Astrophysics

    Our solar system is currently sprinting around the center of the Milky Way at a speed of 26 km/sec. But, we’re not just hurtling through empty space, according to Fellow Jeff Linsky and former graduate student Seth Redfield (now assistant professor of astronomy at Wesleyan University). We’re surrounded by 15 "nearby" clouds of warm gas, all within 50 light years of the Sun. Three of the nearest ones are shown in the figure. 

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  • Attack of the Blobs
    July 09, 2009
    PI(s): Mitch Begelman
    Topic(s): Astrophysics

    Supermassive black holes inside blazar galaxies emit powerful jets of particles traveling in opposite directions near the speed of light. Some are aimed toward the Earth. These jets emit radio waves, which makes them visible to radio telescopes as they streak across the sky. By studying these radio waves, scientists have determined that the jets are traveling at about 99.5% the speed of light and thus exhibit the effects of relativity. The blazars themselves are unusually variable, and many emit ultrahigh-energy γ-rays.

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  • Holy Monodromy!
    July 02, 2009
    PI(s): Heather Lewandowski
    Topic(s): Atomic & Molecular Physics, Nanoscience

    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.

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  • A Light Changing Experience
    April 29, 2009
    PI(s): J. Mathias Weber
    Topic(s): Chemical Physics

    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.

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  • Spinning Out Starspots
    April 17, 2009
    PI(s): Juri Toomre
    Topic(s): Astrophysics

    Our comfortably middle-aged Sun completes a rotation once every 28 days. In contrast, young Sun-like stars spin much faster, sometimes whipping around 10 times as quickly. According to widely accepted theory, these young suns build magnetic fields in their convection zones by dynamo processes. Observations of these stars indicate strong magnetic activity.

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  • The Right Stuff
    April 17, 2009
    PI(s): Jun Ye
    Topic(s): Laser Physics, Nanoscience, Precision Measurement

    In the summer of 2008, Fellow Jun Ye spent a couple of months at CalTech, where he ran into another visiting professor, former JILA Fellow Peter Zoller. Zoller left JILA in 1994 to become Professor of Physics at the University of Innsbruck (Austria). Besides riding bikes together in the mountains, the two men engaged in happy and fruitful discussions about Ye’s work developing a strontium- (Sr-) based optical atomic clock and Zoller’s pioneering research on quantum computing. It took them a matter of a couple of weeks to come up with a basic theoretical framework for a quantum computer based on alkaline-earth metals such as Sr.

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