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For decades, atomic clocks have been the pinnacle of precision timekeeping, enabling GPS navigation, cutting-edge physics research, and tests of fundamental theories. But researchers at JILA, led by JILA and NIST Fellow and University of Colorado Boulder physics professor Jun Ye, in collaboration with the Technical University of Vienna, are pushing beyond atomic transitions to something potentially even more stable: a nuclear clock. This clock could revolutionize timekeeping by using a uniquely low-energy transition within the nucleus of a thorium-229 atom. This transition is less sensitive to environmental disturbances than modern atomic clocks and has been proposed for tests of fundamental physics beyond the Standard Model.

​A team of physicists at the University of Colorado Boulder and the National Institute of Standards and Technology (NIST) has developed a groundbreaking laser-based device capable of analyzing gas samples to identify a vast array of molecules at extremely low concentrations, down to parts per trillion. Their findings were recently published in Nature.

Researchers led by JILA and NIST Fellows and University of Colorado Boulder physics professors Jun Ye and Ana Maria Rey—in collaboration with scientists at the Leibnitz University in Hanover, the Austrian Academy of Sciences, and the University of Innsbruck—proposed practical protocols to explore the effects of relativity, such as the gravitational redshift, on quantum entanglement and interactions in an optical atomic clock. Their work revealed that the interplay between gravitational effects and quantum interactions can lead to unexpected phenomena, such as atomic synchronization and quantum entanglement among particles.

In a new study published in Physical Review Letters, JILA Fellow and University of Colorado Boulder physics professor Cindy Regal, along with former JILA Associate Fellow Jose D’Incao (currently an assistant professor of physics at the University of Massachusetts, Boston) and their teams developed new experimental and theoretical techniques for studying the rates at which light-assisted collisions occur in the presence of small atomic energy splittings. Their results rely upon optical tweezers—focused lasers capable of trapping individual atoms—that the team used to isolate and study the products of individual pairs of atoms.

Researchers at the University of Colorado Boulder have developed a novel method to measure magnetic field orientations using atoms as minuscule compasses. The research, a collaboration between JILA Fellow and ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ physics professor Cindy Regal and Svenja Knappe, a research professor in the Paul M. Rady Department of Mechanical Engineering, was recently published as the cover article in the journal Optica.

Reported recently in a new study published in Nature, a team of researchers, led by JILA and NIST Fellow and University of Colorado Boulder Physics professor Jun Ye, in collaboration with Professor Eric Hudson’s team at UCLA’s Department of Physics and Astronomy, have found a way to make nuclear clocks a thousand times less radioactive and more cost-effective, thanks to a method creating thin films of thorium tetrafluoride (ThF4). 

Physics lab courses are vital to science education, providing hands-on experience and technical skills that lectures can’t offer. Yet, it’s challenging for those in Physics Education Research (PER) to compare course to course, especially since these courses vary wildly worldwide.

To better understand these differences, JILA Fellow and University of Colorado Boulder physics professor Heather Lewandowski and a group of international collaborators are working towards creating a global taxonomy, a classification system that could create a more equitable way to compare these courses. Their findings were recently published in Physical Review Physics Education Research.

JILA and NIST Fellow and ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ Physics Professor Jun Ye has been named a 2024 Highly Cited Researcher by Clarivate. This distinction is awarded to scientists whose work ranks in the top 1% of citations globally. Ye, known for his groundbreaking contributions to precision measurement and atomic, molecular, and optical physics, joins an elite list of researchers shaping the forefront of scientific innovation.

In a recently released NOVA documentary called "Decoding the Universe: Quantum," JILA and NIST Fellow and ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ Physics Professor Jun Ye brings his expertise to the screen, unveiling the mysteries of quantum mechanics and atomic clocks.

JILA postdoctoral researcher Simon Scheidegger has received the prestigious METAS 2024 Award from the Swiss Physical Society (SPS). Scheidegger, who is part of JILA and NIST Fellow Jun Ye's laboratory group, was awarded for his pioneering research on precise measurements of hydrogen energy levels during his PhD at ETH Zurich.