US Joins FCC Effort: Maryland’s Impact

On April 26, 2024, a joint “Statement of Intent between the United States of America and the European Organization for Nuclear Research (CERN) concerning Future Planning for Large Research Infrastructure Facilities, Advanced Scientific Computing, and Open Science” was signed at The White House.  The US-CERN SOI was signed by Deirdre Mulligan, The White House Principal Deputy Chief Technology Officer, and Fabiola Gianotti, the CERN Director-General.   Among other topics, the SOI expresses an intention by the United States to collaborate on a future FCC Higgs Factory, the “Future Circular Collider”, should the CERN Member States determine the project feasible. The planned FCC.The planned FCC

University of Maryland Professor Sarah Eno has played a leading role in establishing US participation in the physics and detectors of the FCC.  Appointed by CERN in 2020 as one of two US representative to the “physics, detector, and experiments” executive committee (with Dmitri Denisov of Brookhaven National Laboratory) Eno spearheaded physics input to the decadal planning process for particle physics, known as the P5 process.  The resulting white paper summarized the exciting physics potential of this facility.  In the resulting P5 report,  US participation in an offshore Higgs factory was recommended.  Recently Eno presented the status of US involvement at the FCC workshop in Annecy, France.  With this announcement, the US will start its formal participation in the development of this international facility.  

Photo from the signing showing from left-to-right: Abid Patwa (DOE), Chris Marcum (The White House OMB and Open Science Point), Deidre Mulligan (The White House PDCTO), Fabiola Gianotti (CERN DG), Rahima Kandahari (US State Department Deputy Assistant Secretary for Science, Technology, and Space Affairs), and Saul Gonzalez (NSF).Photo from the signing showing from left-to-right: Abid Patwa (DOE), Chris Marcum (The White House OMB and Open Science Point), Deidre Mulligan (The White House PDCTO), Fabiola Gianotti (CERN DG), Rahima Kandahari (US State Department Deputy Assistant Secretary for Science, Technology, and Space Affairs), and Saul Gonzalez (NSF).The FCC is planned to be a circular particle accelerator with a circumference around 91 km.  In its first phase, it would collide electrons and positrons with center-of-mass energies and beam intensities that allow collection of the entire sample of the previous LEP electron-positron collider’s Z bosons in three minutes, as well as large samples of W bosons, top quarks, and Higgs particles. Civil construction could begin in the mid 2030s, with data taking in the 2040s.   The accelerator would be located around Geneva, Switzerland, in a tunnel passing near the Jura mountains and under Lake Geneva.  As part of its studies of the Higgs boson, the FCC will study potential connections between it and dark matter, and search for influence of new massive particles and other new physics on its decay properties.  In the future, the same tunnel could house a proton-proton collider similar to the LHC, but with a center-of-mass energy seven times higher.

Maryland has had an impactful participation in the effort.  Besides Eno’s participation in the PED executive committee,  UMD is the lead institution in a plan for a new type of electromagnetic calorimeter for the FCC detectors.  Assistant Professor Chris Palmer has also involved undergraduate students taking PHYS441  in studies of its potential physics impact, which were presented at the second annual US FCC meeting at MIT.  

See the Statement of Intent here and the U.S. Department of State announcement here.

Attendees at the 7th FCC physics workshop in Annecy France (, including Professor Sarah Eno. Click for high-resolution photo.Attendees at the 7th FCC physics workshop in Annecy France (, including Professor Sarah Eno

Ana Maria Rey to Speak at Graduate Commencement Ceremony

For Ana Maria Rey (Ph.D. ’04, physics), the path to a highly successful career as a theoretical physicist and researcher began more than three decades ago in her home country of Colombia, with an inspiring high school physics teacher, the brilliance of Isaac Newton and her own boundless curiosity.

Ana Maria Rey.  Courtesy of same.Ana Maria Rey. Courtesy of same. Ana Maria Rey. Photo courtesy of same. Click image to download hi-res version.

I had a physics teacher in high school, and he was amazing, he taught me about Newton’s laws of motion,” Rey recalled. “I was so excited that I could write an equation and predict the behavior of objects that I kept asking him to give me books so I could keep working and solve more problems because it was all so interesting to me.”

A few years later, after Rey earned her bachelor’s degree in physics in Colombia and began her Ph.D. in physics at the University of Maryland, her future as a scientist began to come into sharper focus. Thanks to a game-changing connection with Distinguished University Professor of Physics and Nobel laureate William Phillips, Rey charted a course toward breakthrough research in atomic and molecular physics and laid the groundwork for a fruitful collaboration with the National Institute of Standards and Technology (NIST), one that is still going strong today.

“For me, NIST and the University of Maryland are just blended. I can’t separate them because they’re so connected,” Rey explained. “UMD gave me a strong foundation, all my research experience, the collaboration experience, everything I learned about how I should talk to experimentalists was thanks to the University of Maryland/NIST partnership. My research was going on at NIST but this only could happen because I was at UMD, so I think when I decided to go to the University of Maryland it was one of the best decisions I have ever made.”

Currently an adjunct professor at the University of Colorado Boulder, Rey has been a NIST Fellow since 2017 and a Fellow of JILA, the joint physics institute of CU Boulder and NIST, since 2012. She has earned a host of prestigious awards including a MacArthur Fellowship and the 2014 Presidential Early Career Award for Scientists and Engineers. In 2019, Rey became the first Hispanic woman to win the Blavatnik National Award for Young Scientists, and in 2023 she was elected to the National Academy of Sciences, one of the highest professional honors for a scientist.   

A big, big honor

In May 2024, nearly 20 years after earning her Ph.D., Rey will return to Maryland—a place that is still very close to her heart—to deliver the keynote speech at the Graduate Commencement Ceremony for UMD’s College of Computer, Mathematical, and Natural Sciences. She’s honored and humbled by the invitation.

“It’s a big, big honor. For me it was really special to feel that a university that has been so important in my career, to determining who I am, has asked me to give a speech like this,” Rey said. “I feel like inspiring students is one of my biggest roles and that’s why I find so touching the possibility to give the commencement speech because maybe this is a way I can tell them how I feel and try to encourage them to make the most of their future.”

A Nobel Prize-winning inspiration

When Rey began her graduate work at UMD she planned to pursue research in plasma physics—that is, until she attended an inspiring lecture by Phillips about his pioneering work with atoms and lasers.

“I heard Bill’s talk about how he was cooling atoms with light, and I found it fascinating. He was fantastic.  I approached my plasma physics advisor Adil Hasam afterward and I told him, ‘I feel that this is the direction that I want to pursue’ and he was totally supportive,” Rey recalled. “He encouraged me to reach out to Charles Clark, who at that time was the chief of the electron optical physics division at NIST and that is what I did.  Charles was very welcoming and told me that I could start working on ultra-cold atoms trapped in periodic potentials using lasers. That is how my Ph.D. adventure started.”

From then on, Rey’s research efforts really took off. At UMD and NIST and later at JILA, her work has focused on atomic, molecular and optical physics as well as condensed matter physics and quantum information science, setting the stage for one of her proudest achievements—her contribution to the most accurate atomic clock ever created.

“My goal is to try to understand the deepest secrets of the universe and try to use them for something useful,” Rey explained. “Understanding the collisions with these atoms has allowed us to create a clock that is really one of the best timekeepers that we have ever been able to construct, and we can now predict that they offer many other, unique possibilities.”

“You need to be excited”

A leading researcher in the Quantum Systems Accelerator, Rey has published more than 200 papers. And, after more than two decades of research, she’s still as motivated and excited about her work as she was the day it all began.

“As a scientist, you have to work a lot to make progress, so you absolutely need to be excited,” Rey explained. “I love it. Every day I’m surrounded by so many exciting experiments and so many things that I need to learn and understand. And every time that I learn something new, it really makes my day.”

Rey hopes she can share that excitement when she speaks to students and their families at the CMNS Graduate Commencement Ceremony in May. Her goal is to inspire the next generation of scientists to create success stories of their own.

“I would like to serve as a role model the way others have done for me,” Rey said. “If I am able to inspire new generations to become physicists, to advance science and do better, that’s one of my great ambitions, and it would be a great honor to feel that I’m doing that. So, my message to them is you have now in your hands the possibility to make a change in the world, so use all the knowledge that you’ve acquired to make that happen.“


Researchers Win UMD Quantum Invention of the Year Award

Since 1987, the University of Maryland has presented an annual Invention of the Year Award to celebrate all the innovative work produced by researchers on the campus. This year JQI researchers and their colleagues have won in the quantum category for a new method for counting particles of light—photons—without destroying them. Non-destructively counting photons has potential uses in quantum computers and quantum networks that store information in quantum states of light.

The co-inventors nominated for their non-destructive photon counting protocol are: 

In 2023, researchers at UMD disclosed a total of 154 inventions, and three teams of inventors were selected as finalists for the award in each of the four categories of Information Sciences, Life Sciences, Physical Sciences and Quantum. The inventions were judged based on their technical merit, the improvements they offer, and their commercial potential and overall benefit to society. 

“It's really nice to be recognized, especially for quantum science because I think sometimes we feel as theorists that we're a little bit more distant from scientific applications, in the sense that a lot of times we're not working on things that are instantly profitable,” says Fechisin. “So it's nice for people to recognize that there's still interesting work and exciting work being done.”

Fechisin is the first author of a paper that the group has posted to the arXiv preprint server that describes the procedure they invented. The team’s approach uses an organized sheet of atoms to absorb photons temporarily and serve as an intermediary. Probing the atoms allows the number of photons that were absorbed to be measured before they are eventually emitted back out of the atoms. 

“Photons are hard to work with and don't typically interact with one another,” Fechisin says. “But atoms are easy to work with, and you can make them interact. So you take information stored in photons, which don't easily talk to each other and are hard to pin down, and you convert the photonic data into atomic data.”

In the paper, the team described the procedure and outlined what is needed from the atoms so that they and the photons can be quantum mechanically tied together and measured, without destroying the photons.

The approach works because when atoms in the array absorb light, they can be made to cycle between quantum states at different rates that depend on how many photons have been absorbed. In their proposal, the team described how a series of measurements can home in on the particular frequency the atoms are cycling at, identifying the corresponding number of photons. After the count is obtained, the atoms can emit the photons. The paper also includes an analysis of how to choose an efficient set of measurements to reliably identify the correct cycling frequency.

“The protocol works in a way that's kind of elegant,” Fechisin says. “You have information stored in these unwieldy photons, you turn it into atomic excitations over which you have a much greater degree of control, and then you just very neatly get this signal, which contains exactly the information that you want.”

The team plans to publish their proposal in a peer-reviewed journal and hopes that other research groups will apply this invention in their future experiments.

Original story by Bailey Bedford:

Charles Tahan Brings His Research Expertise to Thriving UMD Quantum Enterprise

Charles Tahan, who recently stepped down as director of the National Quantum Coordination Office (NQCO), is now bringing his expertise as a quantum physicist and a leader in the quantum research community to the University of Maryland. After leaving NQCO this month, he is taking on new roles at UMD as a visiting research professor in physics and a special advisor to President Darryll J. Pines and Vice President for Research Gregory F. Ball.Charles Tahan in 2022 speaking at QIS Program Day, which is an annual gathering of quantum leaders from across the US Government.  Credit: National Quantum Coordination OfficeCharles Tahan in 2022 speaking at QIS Program Day, which is an annual gathering of quantum leaders from across the US Government. Credit: National Quantum Coordination Office

Tahan served as the director of NQCO beginning in 2020, and before that, he was the founder and director of the Laboratory for Physical Sciences Qubit Collaboratory—a national research center. It serves as a collaborative hub for academia, industry and government research on quantum information processing and associated technologies.

Tahan also leads a quantum information research group that studies topics like various device designs for storing qubits—the basic information building blocks of a quantum computer. In his new role as a special advisor, he will provide recommendations to guide UMD’s efforts in cutting-edge quantum research and transitioning quantum capabilities from the lab to use. Today, there are more than 200 scientists and engineers at UMD exploring topics related to quantum science and technology. The university is a leading member of the Mid-Atlantic Quantum Alliance and is home to the Quantum Startup Foundry and eight centers and institutes dedicated to quantum research.

“As Special Advisor to President Pines and VP for Research Gregory Ball, over the coming months I will help UMD further develop their quantum strategy,” Tahan says. “I will also continue working with my research group as a visiting research professor in the physics department. This aligns really well with my desire to be a physicist and continue to build the quantum community in the DC region, nationally and internationally.”

Story by Bailey Bedford

Sullivan Named Distinguished Scholar-Teacher

Professor Greg Sullivan has been named a University of Maryland Distinguished Scholar-Teacher. The Distinguished Scholar-Teacher Program, established in 1978, honors a small number of faculty members each year who have demonstrated notable success in both scholarship and teaching.

Sullivan received his Ph.D. from the University of Illinois and did postdoctoral work at the University of Chicago before joining the UMD faculty. His research interests span high energy physics and astrophysics.

“Greg very much deserves this recognition,” said Physics chair Steve Rolston. “In his remarkable career, he has won a triple crown, as a key player in three tremendously important findings. And he has always been a superb mentor and fantastic classroom teacher.”

Early in his career, Sullivan was a major contributor to the Collider Detector at Fermilab (CDF), one of two experiments that made the momentous 1995 discovery of the top quark, a subatomic particle whose existence was predicted by the Standard Model. The finding was so significant that decades later, it continues to merit high acclaim, including the 2019 Particle Physics Prize of the European Physical Society.Sullivan (right) at work in AntarcticaSullivan (right) at work in Antarctica

As a UMD assistant professor, Sullivan joined the Super-Kamiokande experiment in Japan, which started operation in 1996 and in 1998 announced the first evidence that neutrinos—the lightest subatomic particles, long believe to be massless—do indeed have mass. This was an enormous reversal of accepted wisdom.  So important is the realization of neutrino mass that the Principal Investigator of the Super-Kamiokande experiment received the 2015 Nobel Prize for Physics and the collaboration was honored with the 2016 Breakthrough Prize in Physics.

Sullivan at the South PoleSullivan at the South PoleFollowing the Super-Kamiokande success, Sullivan turned to a scientific and engineering marvel: the cosmic neutrino-seeking IceCube experiment at the South Pole. Painstakingly, in a near-decade-long effort in frigid conditions, scientists drilled 86 1.5 mile-deep holes in the pristine Antarctic ice and equipped them with ultra-sensitive detectors, creating a massive observatory of unprecedented volume.  Sullivan was deeply involved in planning IceCube and was elected to the crucial position of Spokesperson (chief scientist) as it began operation. In two years, the collaboration published the first observation of cosmic neutrinos. Physics World named this feat the 2013 Breakthrough of the Year.  The discoveries continue; just months ago, IceCube announced detection of neutrinos from our Milky Way galaxy. And IceCube will continue to play a very important role in the evolving world of multimessenger astronomy, the collaborative effort to turn varied earth and space-based telescopes in unison to track emergent cosmic phenomena.

Sullivan has served as the thesis advisor for 17 students. He was the department’s Associate chair for Graduate Education from 2006-09. More recently, he has served as co-chair of our department’s Quantum Education Committee.

He will give a Distinguished Scholar-Teacher lecture in the fall 2024 semester.