News & Research Highlights

The hunt was afoot within the laboratory of JILA and NIST Fellow Ralph Jimenez as his team continued to unravel the mystery of entangled two-photon absorption. Entangled photons are pairs of light particles whose quantum states are not independent of each other, so they share aspects of their properties, such as their energies and angular momenta. For many years, these photons have been studied by physicists who are trying to create quantum networks and other technologies. The Jimenez lab has been researching whether entangled photons can excite molecules with greater, even super, efficiency as compared with normal photons. 

In a new paper published in the Journal of Physical Chemistry Letters, Jimenez and his team report a new experimental setup to search for the cause of a mysterious fluorescent signal that appears to be from entangled photon excitation. According to Jimenez: “We built a setup where you could use either a classical laser or entangled photons to look for fluorescence. And the reason we built it is to ask: ‘What is it that other people were seeing when they were claiming to see entangled photon-excited fluorescence?’ We saw no signal in our previous work published a year ago, headed by Kristen Parzuchowski. So now, we're wondering, people are seeing something, what could it possibly be? That was the detective work here.” The results of their new experiments suggested that hot-band absorption (HBA) by the subject molecules, could be the potential culprit for this mysterious fluorescent signal, making it the prime suspect. 

JILA Fellow Heather Lewandowski has been honored in the 2022  President’s Teaching Scholars Program (PTSP), which recognizes CU faculty who skillfully integrate teaching and research at an exceptional level. Lewandowski's laboratory focuses on both cold molecular physics and physics education research. Her physics education research program studies ways to increase students' proficiency in scientific practices such as using models and quantitative reasoning in experimental physics. 

Physicists develop some of the most cutting-edge technologies, including new types of lasers, microscopes, and telescopes. Using lasers, physicists can learn more about quantum interactions in materials and molecules by taking snapshots of the fastest processes, and many other things. While lasers have been used for decades, their applications in technology continue to evolve. One such application is to generate and control x-ray laser light sources, which produce much shorter wavelengths than visible light. This is important because progress in developing x-ray lasers with practical applications had essentially stalled for over 50 years. Fortunately, researchers are beginning to change this by using new approaches. In a paper published in Science Advances, a JILA team, including JILA Fellows Margaret Murnane, and Henry Kapteyn, manipulated laser beam shapes to better control properties of x-ray light.

JILA physicists have measured Albert Einstein’s theory of general relativity, or more specifically, the effect called time dilation, at the smallest scale ever, showing that two tiny atomic clocks, separated by just a millimeter or the width of a sharp pencil tip, tick at different rates.

The experiments, described in the Feb. 17 issue of Nature, suggest how to make atomic clocks 50 times more precise than today’s best designs and offer a route to perhaps revealing how relativity and gravity interact with quantum mechanics, a major quandary in physics.
 

JILA Fellow Cindy Regal has helped consult on a new mural placed in Washington Park in Denver, Colorado. The mural, titled Leading Light, loosely alludes to AMO physics, which Regal studies by using laser beams. With bright yellows and vivid pinks, the mural depicts four women interacting with different blue spheres, representing electrons. One woman wears sunglasses, modeled on thelaser goggles that JILAns wear for lab safety. The artist, Amanda Phingbodhipakkiya, found Regal's work captivating. “We share a vision to not only uplift women in STEM and to bring science and our society closer together, but also to foster dynamic and organic relationships with science in everyone, whether or not they choose to become scientists,” the artist said.

Two JILA graduate students were awarded "Oustanding Service Awards" from the Physics department at the University of Colorado Boulder. These awards are given each semester. 

Antonio Vigil, a recently graduated JILA undergraduate has been named an "Outstanding Undergraduate" by the College of Arts and Sciences at the University of Colorado Boulder. Vigil recently graduated summa cum laude after working for three years at JILA. 

How atoms interact with light reflects some of the most basic principles in physics. On a quantum level, how atoms and light interact has been a topic of interest in the worldwide scientific community for many years. Light scattering is a process where incoming light excites an atom to a higher-lying energy state from which it subsequently decays back to its ground state by reemitting a quantum of light. In the quantum realm, there are many factors that affect light scattering. In a new paper published in Science, JILA and NIST Fellow Jun Ye and his laboratory members report on how light scattering is affected by the quantum nature of the atoms, more specifically, thequantum statistical rule such as the Pauli Exclusion Principle.

JILA and NIST Fellow Jun Ye has been awarded the 2022 Herbert-Walther-Award from the German Physical Society and OPTICA (formerly OSA). This award recognizes distinguished contributions in quantum optics and atomic physics as well as leadership in the international scientific community.

Gravimetry, or the measurement of the strength of a gravitational field (or gravitational acceleration), has been of great interest to physicists since the 1600s. One of the most precise ways to measure gravitational acceleration is to use an atom interferometer. There are many different types of atom interferometers but so far all operate using uncorrelated atoms that are not entangled. To build the best one allowed in nature, it requires harnessing the power of quantum entanglement. However, making a quantum interferometer with entangled atoms is challenging. JILA Fellows Ana Maria Rey and James K. Thompson have published a paper in Physical Review Letters that discusses a new protocol that could make entangled quantum interferometers easier to produce and use.

JILA and NIST Fellow Jun Ye has been named a 2021 Clarivate Highly Cited Researcher. This means that Ye is one of the 0.1%, of the world's researchers who receive this title. Clarivate™ is a data analytics company that identifies the world’s most influential researchers ─ the select few who have been most frequently cited by their peers over the last decade. Ye’s many published papers over the last year have been ranked in the top 1% by citations for field and year in the Web of Science™, according to Clarivate. Well done Dr. Ye! 

JILA Fellow Andreas Becker is one of the 11 University of Colorado Boulder faculty to be awarded a 2021 Distinguished Professor title. CU Distinguished Professors are tenured faculty members who give outstanding work in research or creative work and have a reputation of excellence in promoting learning and student engagement in the research process as well as dedicated to the profession, the university, and its affiliates.

JILA and NIST Fellow Jun Ye has been awarded the Niels Bohr Institute Medal of Honor for 2021. This award was established in 2010 to mark the 125th anniversary of Niels Bohr’s birth. The medal is awarded annually to a particularly outstanding researcher who is working in international cooperation and exchange of knowledge, two qualities exemplified by Bohr himself.

The second quantum revolution is underway, a period marked by significant advances in quantum technology, and huge discoveries within quantum science. From tech giants like Google and IBM, who build their own quantum computers, to quantum network startups like Aliro Quantum, companies are eager to profit from this revolution. However, doing so takes a new type of workforce, one trained in quantum physics and quantum technology. The skillset required for this occupation is unique, and few universities expose students to real-world quantum technology. 

Congratulations to JILA Fellow Dana Anderson for winning the 2021 Willis E Lamb award for Laser Science and Quantum Optics.

The award recognizes Dana's, "excellent contributions to quantum optics and electronics". The Anderson Group is currently involved in state of the art ultracold atom research with applications in atomtronics, atom interferometry and neutral atom quantum computing. 

The Willis E. Lamb Award for Laser Science and Quantum Optics is presented annually for outstanding contributions to the field. The award honors Willis E. Lamb, Jr., famous laser scientist and 1955 winner of the Nobel Prize in physics, who gave us many seminal insights and served as our guide in so many areas of physics and technology.

The Bose-Einstein Condensate (BEC) has been studied for decades, ever since its prediction by scientists Satyandra Nath Bose and Albert Einstein nearly 100 years ago. The BEC is a gas of atoms cooled to almost absolute zero. At low enough temperatures, quantum mechanics allows the locations of the atoms in the BEC to be uncertain to the extent that they can’t be located individually in the gas. The BEC has a special history with JILA, as it was at JILA that the first gaseous condensate was produced in 1995 by JILA Fellows Eric Cornell (NIST) and Carl Wieman (University of Colorado Boulder). Since 2005, research on dipolar BEC has continued, using different theories to describe the droplet’s interactions. In a paper recently published in Physical Review A, first author, and graduate student, Eli Halperin and JILA fellow John Bohn theorize a way to study the BEC using a hyperspherical approach. While the name may sound intimidating, the hyperspherical approach is simply a systematic way to look at a many-body problem. The many body problem refers to a large category of problems regarding microscopic systems with interacting particles. Bohn and Halperin applied this approach to a dipolar BEC specifically.

Atomic clocks have been heavily studied by physicists for decades. The way these clocks work is by having atoms, such as rubidium or cesium, that are "ticking" (that is, oscillating) between two quantum states. As such, atomic clocks are extremely precise, but can be fragile to shaking or other perturbations, like temperature fluctuations. Additionally, these clocks need a special laser to probe the clock. Both factors can make atomic clocks imprecise, difficult to study, and expensive to make.
A team of physicists are proposing a new type of laser that could change the future path of atomic clocks. In this team, JILA Fellow Murray Holland and Research Associate Simon Jäger theorized a new type of laser system in a paper recently published in Physical Review Letters. 

JILA Fellow Thomas Perkins has been awarded the 2021 Outstanding Postdoc Mentor Award. This award recognizes mentors who have gone above and beyond to support their postdocs. Perkins was nominated by postdoc David Jacobson, who praised Perkins' effort to help Jacobson apply and receive the prestigious NIH K99 “Pathway to Independence” Award. 

JILA Fellow Graeme Smith also won the 2021 Outstanding Postdoc Mentor Award, being nominated by CU Boulder postdoc Vikesh Siddhu and former CU Boulder postdoc, Felix Leditzky. Leditzky said Smith “played an integral part in guiding me through the process and helping me achieve this career goal. I aim to pay forward the trust and support that I received from him.”

Jun Ye, fellow at the National Institute of Standards and Technology (NIST) and professor adjoint of physics at CU Boulder, has been awarded the 2022 Breakthrough Prize in Fundamental Physics for his pioneering research on atomic clocks. Ye has been a physicist at JILA, a joint institute of NIST and CU Boulder, for more than 20 years. 

The basic question of how strands of nucleic acids (DNA and RNA) fold and hybridize has been studied thoroughly by biophysicists around the globe. In particular, there can be unexpected challenges in obtaining accurate kinetic data when studying the physics of how DNA and RNA fold and unfold at the single molecule level. One problem comes from temporal camera blur, as the cameras used to capture single photons emitted by these molecules do so in a finite time window that can blur the image and thereby skew the kinetics. In a paper published in the Journal of Physical Chemistry B, JILA Fellow David Nesbitt, and first author David Nicholson, propose an extremely simple yet broadly effective way to overcome this camera blur.