Research Highlights

Bringing molecules down to ultracold temperatures takes a mythic approach, but the Ye Group finds that their new scheme can hold up under tough conditions.

The secrets of nature are written in nanoscale. Now the Raschke Group has found a way to read those secrets.

The world is out-of-equilibrium, and JILA scientists are trying to learn what rules govern the dynamic systems that make our universe so complex and beautiful, from black holes to our living bodies.

In a new study from the Kapteyn-Murnane Group, ultrafast laser pulses can precisely cut through and manipulate the interaction between electrons and phonons in tantalum diselenide, changing its properties.

Could quantum entanglement improve our cell phone networks? The Graeme Smith Group at JILA found the answer by playing mathematical logic games.

Quantum technologies could process information even faster if they could harness the speed of light. Using gold nanostars, the Nesbitt Lab have found a way to use light to steer electric currents. 

JILA's Jimenez Lab has developed a flow cytometry systems which take sorting time from days to hours.

Quantum drums can get around distracting noise with a new measurement technique—one that perfectly demonstrates the Heisenberg uncertainty principle.

Atoms could live in their excited states forever by reaching a dark state.

New research from the Cornell Group suggests that the van der Waals universality may have limitations.

How do you hear--and study--the quietest sound in the universe? With a special microphone and speaker. 

An advance from the Raschke group could free quantum technology from ultra-cold temperatures.

Using Feshbach resonance, physicists have found that they can control a dynamical phase transition in an out-of-equilibrium state. 

It's hard to read a clock with hands that wobble. The Ye Group has found a way to steady their optical atomic clock using a new cavity.

While we've known for a while that black holes could rip stars apart, we don’t know why these events occur so frequently. Now, a model by JILA researchers explaining this discrepancy is shown to be promising after passing its first reality test.

It's tough to get tightly-wound balls of DNA to lay down flat and straighten out to get their picture taken. A new technique from the Perkins group gets a crisp, clear picture in just five minutes.

Researchers at JILA and the University of Salamanca have found a new property of light, one that creates a whirling vortex that can speed itself up. 

Getting a cluster state of perfectly entangled atoms for quantum computing may be easier using a tool in JILA's laboratory.

JILA researchers have proposed an experiment that would allow them to study rapid scrambling of quantum information, similar to what happens at the event horizon of a black hole. 

Trapping single atoms is a bit like herding cats, which makes researchers at the University of Colorado Boulder expert feline wranglers. In a new study, a team led by physicist Cindy Regal showed that it could load groups of individual atoms into large grids with an efficiency unmatched by existing methods.  

By using ultrafast lasers to measure the temperature of electrons, JILA researchers have discovered a never-before-seen state in an otherwise standard semiconductor. This research is the most recent demonstration of a new technique, called ultrafast electron calorimetry, which uses light to manipulate well-known materials in new ways.

JILA researchers have demonstrated a much easier, faster and more precise way to understand the structure and function of the HIV RNA molecule, especially the HIV RNA hairpin. Furthermore, the techniques developed for this research promise to allow a wider range of users to study similar biological molecules, as they are built upon commercially available and user-friendly atomic force microscopes, or AFMs.

When the Ye group measured the total quantum state of buckyballs, we learned that this large molecule can play by full quantum rules. Specifically, this measurement resolved the rotational states of the buckyball, making it the largest and most complex molecule to be understood at this level.

JILA researchers have, for the first time, trapped a single alkaline-earth atom and cooled it to its ground state. To trap this atom, researchers used an optical tweezer, which is a laser focused to a pinpoint that can hold, move and manipulate atoms. The full motional and electronic control wielded by this tool enables microscopically precise studies of the limiting factors in many of today’s forefront physics experiments, especially quantum information science and metrology. 

Understanding chemistry requires understanding both molecules and quantum physics. The former defines the start and end of chemical reactions, the latter dictates the dynamics in between. JILA researchers now have a better understanding of both.

In the vast stretches between solar systems, heat does not flow and sound does not exist. Action seems to stop, but only if you don’t look long enough. Violent and chaotic actions occur in the long stretches of outer space. These chemical reactions between radicals and ions are the same reactions underlying the burn of a flame and floating the ozone above our planet. But they’re easy to miss in outer space because they’re very rare.

Quantum computers are set to revolutionize society. With their expansive power and speed, quantum computers could reduce today’s impossibly complex problems, like artificial intelligence and weather forecasts, to mere algorithms. But as revolutionary as the quantum computer will be, its promises will be stifled without the right connections. Peter Burns, a JILA graduate student in the Lehnert/Regal lab, likens this stifle to a world without Wi-Fi.  

With the advent of the laser, the fuzzy bands glowing from atoms transformed into narrow lines of distinct color. These spectral lines became guiding beacons visible from the quantum frontier. More than a half century later, we stand at the next frontier. The elegant physics that will decode today’s mysteries (such as dark matter, dark energy, and the stability of our fundamental constants, to name a few) is still shrouded in shadows. But a new tool promises illumination. 

The chaos within a black hole scrambles information. Gravity tugs on time in tiny, discrete steps. A phantom-like presence pervades our universe, yet evades detection. These intangible phenomena may seem like mere conjectures of science fiction, but in reality, experimental comprehension is not far, in neither time nor space. Astronomical advances in quantum simulators and quantum sensors will likely be made within the decade, and the leading experiments for black holes, gravitons, and dark matter will be not in space, but in basements – sitting on tables, in a black room lit only by lasers.

The hardest problems are never solved by one person. They are solved by teams; or in the case of science, collaborations. It took a collaboration of 17 researchers, including four JILA fellows and another six JILA affiliates, just a little over five years to achieve robust polarization control over isolated attosecond (one billionth of a billionth of a second) pulses of extreme-ultraviolet light. 

A large fraction of JILA research relies on laser cooling of atoms, ions and molecules for applications as diverse as world-leading atomic clocks, human-controlled chemistry, quantum information, new forms of ultracold matter and the search for new details of the origins of the universe. JILAns use laser cooling every day in their research, and have mastered arcane details of the process.

JILA researchers have created a laser-controlled "electron faucet", which emits a stable stream of low-energy electrons. These faucets have many applications for ultrafast switches and ultrafast electron imaging. The electron faucet starts with gold, spherical nanoshells. “They are glass cores with a thin, gold layer over them,” said Jacob Pettine, the graduate student on the project. These nanoshells are truly on the nanoscale, measuring less than 150 nanometers in diameter, which is “something like a thousandth of the size of a human hair,” said Pettine.

“Well, this isn’t going to work.” That was recent JILA graduate Carrie Weidner’s first thought when her advisor, JILA Fellow Dana Anderson, proposed the difficult experiment: to build an interferometer unlike any before – an interferometer of shaking atoms. But the grit paid off, as this compact and robust interferometer outperforms all others in filtering and distinguishing signal direction. While the designs of most atom interferometers are symmetric and elegant, Weidner says the shaken-lattice experiment proposed by Anderson “is more like broken eggs.”

JILA Fellow Dana Z. Anderson, JILA visiting scientist Alex Zozulya, and a colleague from the Worcester Polytechnic Institute postulate that the ultracold coherent atoms in a Bose-Einstein Condensate (BEC) could be configured to act like electrons in a transistor. An “atom transistor” would exhibit absolute and differential gain, as well as allow for the movement of single atoms to be resolved in a precision scientific measurement.

We all know what a tenth of a second feels like. It’s a jiffy, a snap of the fingers, or a camera shutter click. But what does 14 billion years–the age of the universe–feel like? JILA’s atomic clock has the precision to measure the age of the universe to within a tenth of a second. That sort of precision is difficult to intuit. Yet, JILA’s atomic clock, which is the most precise clock in the world, continues to improve its precision. The latest jump in precision, of nearly 50 percent, came about from a new perspective.

Jupiter is large enough to fit 1,300 Earths inside, and still have room. But like all planets, Jupiter was once nothing more than a cosmic dust bunny. A team of physicists at JILA and the University of Arizona, led by JILA Senior Research Associate Jake Simon, are studying how cosmic pebbles­­—­starting only a millimeter in size—can lead to the formation of planetesimals, the football-field-to-Delaware-sized primordial asteroids whose development defined our solar system’s architecture.

Researchers from the Raschke group are lighting up dark excitons. Specifically, the Raschke group developed a method to observe dark excitons in a 2D (i.e., a single layer of atoms) semiconductor at room temperature. This observation is an exciting development in the story of dark exciton applications, which includes quantum information processing and fundamental studies of complex semiconductor materials.

Magnets hold cards to your fridge, and store data in your computer. They can power speakers, and produce detailed medical images. And yet, despite millennia of use, and centuries of study, magnetism is still far from fully understood.

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.

Astrophysicist Jeff Linsky and his colleagues recently created a sophisticated mathematical model of the outer atmosphere of the small M-dwarf star called GJ832. The new model fits well with spectral observations of the star made with the Hubble Space Telescope (HST). This accomplishment bodes well for two reasons: First, it provides a tool for better understanding M-dwarf stars––the most common type of star in our galaxy.

The Rey and Ye groups discovered the strange rules of quantum baseball earlier this year. But now, quantum baseball games happen faster, and players (dipolar particles) are no longer free to move or stand wherever they want. Players must not only be stronger to jump and catch the balls (photons), but also more organized. At the same time, they must be good spinners. And, only a small amount of disorder is tolerated! The fast spinning of the players and their fixed positions have made quantum baseball a whole new game!