Research Highlights

The reaction, at first glance, seems simple. Combustion engines, such as those in your car, form carbon monoxide (CO). Sunlight converts atmospheric water into a highly reactive hydroxyl radical (OH). And when CO and OH meet, one byproduct is carbon dioxide (CO₂) ­– a main contributor to air pollution and climate change.

The actors are molecules. The plot, broken molecular bonds. JILA Fellow Ralph Jimenez and a team of detector experts at the National Institute of Standards and Technology (NIST) are working together to make X-ray movies of a molecular drama. The team at NIST built a microcalorimeter X-ray spectrometer capable of performing time-resolved spectroscopy; in other words: a camera to film molecules. They use this camera to learn how molecules break their bonds – do the ­electrons rearrange, do the other atoms quake?

Why are we here? This is an age-old philosophical question. However, physicists like Will Cairncross, Dan Gresh and their advisors Eric Cornell and Jun Ye actually want to figure out out why people like us exist at all. If there had been the same amount of matter and antimatter created in the Big Bang, the future of stars, galaxies, our Solar System, and life would have disappeared in a flash of light as matter and antimatter recombined.

Imagine A Future . . . The International Moon Station team is busy on the Moon’s surface using sensitive detectors of gravity and magnetic and electric fields looking for underground water-rich materials, iron-containing ores, and other raw materials required for building a year-round Moon station. The station’s mission: launching colonists and supplies to Mars for colonization. Meanwhile, back on Earth, Americans are under simultaneous assault by three Category 5 hurricanes, one in the Gulf of Mexico and two others threatening the Caribbean islands. Hundreds of people are stranded in the rising waters, but thanks precision cell-phone location services and robust cell-tower connections in high wind, their rescuers are able to accurately pinpoint their locations and send help immediately.

Newly minted JILA Ph.D. Catherine Klauss and her colleagues in the Jin and Cornell group decided to see what would happen to a Bose-Einstein condensate of Rubidium-85 (⁸⁵Rb) atoms if they suddenly threw the whole experiment wildly out of equilibrium by quickly lowering the magnetic field through a Feshbach resonance.

Quantum computers require systems that can encode, manipulate, and transmit quantum bits, or qubits. A creative way to accomplish all this was recently demonstrated by Adam Reed and his colleagues in the Lehnert group. The researchers converted propagating qubits (encoded as superpositions1 of zero and one microwave photons) into the motion of a tiny aluminum drum. The successful conversion is considered a key step in using a mechanical drum to (1) transfer quantum information between microwave and optical frequencies or (2) store quantum information inside a quantum computer.

Researchers at JILA and around the world are starting a grand adventure of precisely controlling the internal and external quantum states of ultracold molecules after years of intense experimental and theoretical study. Such control of small molecules, which are the most complex quantum systems that can currently be completely understood from the principles of quantum mechanics, will allow researchers to probe the quantum interactions of individual molecules with other molecules, investigate what happens to molecules during collisions, and study how molecules behave in chemical reactions. 

When Steven Spielberg’s adorable extra-terrestrial, E. T., wanted to phone home, he should have contacted an information theorist like JILA’s Graeme Smith. Smith could have at least explained how E. T. could have used a cell phone to send a low-noise message to a cell phone tower,¹ and from there––well to outer space (which is a problem that's much, much harder to solve than cell phone to cell phone tower transmissions).

The Sun isn’t working the way we thought it did. Many astrophysicists haven't actually understood one aspect of how the Sun worked––until former senior research associate Nick Featherstone and senior research associate Brad Hindman set the record straight.

The Perkins group has made dramatic advances in the use of Atomic Force Microscopes (AFMs) to study large single biomolecules, such as proteins and nucleic acids (DNA, RNA), that are important for life. After previously improving AFM measurements of biomolecules by orders of magnitude for stability, sensitivity and time response, the Perkins group has now developed ways to make these precision biomechanical measurements up to 100 times faster than previously possible––obtaining useful information in hours to days rather than weeks to months. 

Getting lasers to have a precise single frequency (color) can be trickier than herding cats. So it’s no small accomplishment that the Thompson group has figured out how to use magnetic fields to create atomic cowpokes to wrangle a specific single color into place so that it doesn’t wander hither and yon. The researchers do this with a magnetic field that causes strontium atoms in an optical cavity to stop absorbing light and become transparent to laser light at one specific color. What happens is that the magnetic field creates a transparent window that serves as a gate to let only light of a single frequency pass through.

The Kapteyn-Murnane group has come up with a novel way to use fast bursts of extreme ultraviolet light to capture how strongly electrons interact with each other in materials. This research is important for figuring out how quickly materials can change their state from insulating to conducting, or from magnetic to nonmagnetic. In the future such fast switching may lead to faster and more efficient nanoelectronics.

JILA and NIST scientists are hot on the trail of understanding quantum correlations (or entanglement) among groups of quantum particles such as atoms or ions. Such particles are the building blocks of larger and larger chunks of matter that make up the everyday world. Interestingly, correlated atoms and ions exhibit exotic behaviors and accomplish tasks that are impossible for noninteracting particles. Therefore, understanding how entanglement is generated in those systems is not only central to comprehending our world, but also advancing technology.

The Regal group recently met the challenge of measurements in an extreme situation with a device called an interferometer. The researchers succeeded by using creative alterations to the device itself and quantum correlations. Quantum correlations are unique, and often counterintuitive, quantum mechanical interactions that occur among quantum objects such as photons and atoms. The group exploited these interactions in the way they set up their interferometer, and improved its ability to measure tiny motions using photons (particles of light).

The first results are in from a new search for the axion, a hypothetical particle that may constitute dark matter. Researchers in the Haloscope At Yale Sensitive to Axion Cold Dark Matter (HAYSTAC) recently looked for evidence of the axion, but so far they have found none in the small 100 MHz frequency range between 5.7 and 5.8 GHz.

Dennis Gardner and his coworkers in the Kapteyn-Murnane group accomplished two major breakthroughs in imaging tiny structures much too small to be seen with visible light microscopes: (1) for the first time in the extreme ultraviolet (EUV) or soft X-ray region, they achieved a resolution smaller than the wavelength of the light; and (2) for the first time, they obtained high resolution quantitative imaging of near periodic tiny objects (structures with repetitive features).

The lovely Crab Nebula was created by a supernova and its spinning-neutron-star remnant known as a pulsar. Pulsar wind nebulae, such as the Crab, shine because they contain plasmas of charged particles, such as electrons and positrons, traveling at near the speed of light. A key question in astrophysics has long been: What process accelerates some of the charged particles in plasmas to energies much higher than the average particle energy, giving them near light speeds?

The Perkins group continues to extend the performance of its unique Atomic Force Microscope (AFM) technology, revealing for the first time a dozen new short-lived intermediate states in the folding and unfolding of a membrane protein that controls the exchange of chemicals and ions into and out of living cells. Measuring the energetics and dynamics of membrane proteins is crucial to understanding normal physiology and disease, and the Perkins group’s observation of multiple new folding/unfolding states shines new light on these cellular “gatekeepers.”

In the Ye group’s new quantum simulation experiment, cold strontium atoms, which are analogs of electrons, are allowed to tunnel between the pancakes that confine the atoms with laser light. Because the atoms moving in an array of pancakes are analogs of electrons moving in solids, such studies are expected to shed light on the complex physics of metals and other solids. Credit:  The Ye group and Steve Burrows, JILA

Deborah Jin, Jun Ye, and their students wrote a review during the summer of 2016 for Nature Physics highlighting the accomplishments and future directions of the relatively new field of ultracold-molecule research. The field was pioneered by the group’s creation of the world’s first gas of ultracold potassium-rubidium (KRb) molecules in 2008.