NSF, Department of Energy Grants Enable Physicists to Continue Cutting-Edge Research in Neutrino Discovery

From Syracuse University, September 18, 2022: Researchers at Syracuse University have received two new grants that will expand their work with physicists from around the world on projects that include MicroBooNE, DUNE and NOvA. The support comes from the NSF and DOE and will enable graduate and undergraduate students to work on everything from detector construction and operation at Fermilab and Syracuse, to final data analysis and software development.

The U.S. Department of Energy’s Fermi National Accelerator Laboratory Director Lia Merminga announced that Bonnie Fleming has been named Fermilab’s chief research officer and deputy director responsible for leading all areas of science and technology, effective Sept. 6, 2022.

Fleming is a familiar member of the Fermilab community, having worked on Fermilab experiments since 1997. Currently the lab’s advisor for science and technology, she began her career at Fermilab as a Columbia University graduate student, working on the NuTeV experiment and later as a Lederman Fellow working on MiniBooNE.

“Bonnie is uniquely qualified to serve as the new Fermilab’s deputy director for science and technology and chief research officer,” Merminga said. “As an internationally recognized expert in neutrino physics, the founding spokesperson for the ArgoNeuT and the MicroBooNE neutrino experiments, and a pioneer in developing the Liquid Argon Time Projection Chambers detector technology employed for these experiments as well as for the international DUNE experiment hosted by Fermilab, Bonnie brings vast experience, expertise, enthusiasm and collaboration to her new role.”

Fleming has served on several community panels in particle physics, including the 2014 P5 High Energy Physics Advisory Panel subpanel, and more recently, she was the co-chair for the DOE Basic Research Needs on Instrumentation and the ongoing HEPAP subpanel on International Benchmarking, as well as a member of the current National Academies Decadal Survey in particle physics.

“Fermilab has always been like home to me,” Fleming said. “I look forward to my new role and working with my colleagues toward Fermilab’s scientific vision and mission and to supporting the projects Fermilab has underway now and will execute in the future.”

Since 2004, Fleming has been on faculty at Yale University and will transition to University of Chicago’s faculty as a professor of physics and the Enrico Fermi Institute, also effective Sept. 6.

Fermilab would like to recognize and thank Joe Lykken, Fermilab’s current chief research officer, for his longstanding excellence in lab leadership. Effective Sept. 6, he will continue in his role as head of the Fermilab Quantum Institute and assist with transition of the chief research officer role.

A five-member delegation from the French National Centre for Scientific Research’s Institut National de Physique Nucléaire et de Physique des Particules, led by IN2P3 director Reynald Pain, visited the U.S. Department of Energy’s Fermi National Accelerator Laboratory on Sept. 2. Fermilab Director Lia Merminga and Whitney Begner, deputy manager of DOE’s Fermi Site Office, welcomed the visitors.

The delegation met with Fermilab management and scientists to discuss IN2P3-Fermilab collaboration in accelerator and neutrino programs. The visitors also obtained an overview of the lab’s quantum research, scientific computing efforts and theory programs. IN2P3 is a major partner of the PIP-II particle accelerator project and the international Deep Underground Neutrino Experiment, hosted by Fermilab.

The IN2P3 delegation also virtually met with Harriet Kung, deputy director for Science Programs in the DOE Office of Science and acting associate director for the DOE Office of High Energy Physics. She thanked the delegation for their continued support and the substantial contribution of key technologies in the neutrino and accelerator programs.

“IN2P3’s collaboration with Fermilab and their contributions to PIP-II and DUNE are examples of how important international partnerships are in advancing accelerator technologies and global neutrino research,” said Merminga.

The delegation spent the day at Fermilab talking with scientists and touring various research facilities. The visit provided an opportunity for the delegation to see the advances in the LBNF/DUNE neutrino project and the PIP-II particle accelerator project. The tour included Fermilab’s work on superconducting cavities for PIP-II as well as superconducting magnets for the High-Luminosity Large Hadron Collider upgrade; the assembly of the Short Baseline Neutrino Detector and work on the CMS detector upgrade at the LHC. The visitors also toured the Superconducting Quantum Materials and Systems Center.

In addition to Director Pain, IN2P3 delegates on the visit included Deputy Director Berrie Giebels; Laurent Vacavant, scientific director for particle and hadronic physics; Arnaud Lucotte, scientific director for accelerators, detectors and technology; and Marcella Grasso, scientific director for nuclear physics and applications.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

How long have you been at the U.S. Department of Energy’s Fermi National Accelerator Laboratory?

I started end of October 2021.

How did you get interested in physics?

I think it started from my family — not only [my interest] in physics but in science — because my mother is a physics teacher. I remember her teaching me, explaining things scientifically to me at a very young age. She always encouraged me to pursue a Ph.D. in physics.

In my country [Sri Lanka], if we want to continue our studies in science, we can do math, chemistry and physics subjects in high school. After high school, I did my bachelor’s studies at the University of Peradeniya, Sri Lanka. There, I got selected for a physics special program, which is a four-year course. From there, I received a scholarship to come here [to the U.S.] to do higher studies. I came here in 2015 and did my master’s and Ph.D. at Old Dominion University, Virginia, in collaboration with Thomas Jefferson National Accelerator Facility. It’s been a long journey, but it started from my family.

What are the projects you’re working on now at Fermilab?

Currently, I’m working on the Booster. My investigation is about the electron cloud existence: whether there is an electron cloud present in the Booster and if so, whether it would impact the PIP-II-era Booster — because PIP-II requires an intensity upgrade in the Booster.

What is an electron cloud?

Stray electrons always exist inside the beam pipe, and the electromagnetic fields of the beam can accelerate these electrons. When such electrons impact vacuum chamber walls, secondary electrons are generated according to their impact energy and the secondary electron yield of the surface. Repeating this process can lead to an avalanche, creating the electron cloud. The electron cloud acts as a lens, providing additional focusing or de-focusing to the beam, and can severely limit the performance of high-intensity proton accelerators [by causing] transverse instabilities, transverse emittance growth, particle losses, etc. That is why we want to investigate the effect of the electron cloud in the PIP-II­-era Booster.

Is there anything that you are most excited about for PIP-II in the future?

I think altogether, the Deep Underground Neutrino Experiment [that PIP-II will power] is fascinating. Making the world’s most intense high-energy neutrino beam! I’m lucky to be a part of it.

What’s the most rewarding part of your job?

I think it’s understanding, finding solutions and learning something new.

What is the most challenging part of your work?

This is my first position after my Ph.D., so everything is new, working as a scientist. It’s a bit different area of work: The machine is vast, and there’s a lot to learn. But it is like a dream come true to get a chance to work at Fermilab. I feel fortunate.

What do you like best about working at Fermilab?

I like the people. I feel welcomed and always helped; I never had a problem. Also, I like all the landscape and all the cultural diversity and the outdoor activities. It’s like a family altogether; it’s not only work.

What do you like to do when you are not at work?

I like traveling. I like being outside, driving and listening to music. I like the sky, the evening sky and the sunset here; you can look at it forever.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

 

Silicon is a material widely used in computing: It is used in computer chips, circuits, displays and other modern computing devices. Silicon is also used as the substrate, or the foundation of quantum computing chips.

Researchers at the Superconducting Quantum Materials and Systems Center, hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, demonstrated that silicon substrates could be detrimental to the performance of quantum processors. SQMS Center scientists have measured silicon’s effect on the lifespan of qubits with parts-per-billion precision. These findings have been published in Physical Review Applied.

New approaches to computing

Calculations once performed on pen and paper have since been handed to computers. Classical computers rely on bits, 1 or 0, which have limitations. Quantum computers offer a new approach to computing that relies on quantum mechanics. These novel devices could perform calculations that would take years or be practically impossible for a classical computer to perform.

Using the power of quantum mechanics, qubits—the basic unit of quantum information held within a quantum computing chip—can be both a 1 and a 0 at the same time. Processing and storing information in qubits is challenging and requires a well-controlled environment. Small environmental disturbances or flaws in the qubit’s materials can destroy the information.

Qubits require near-perfect conditions to maintain the integrity of their quantum state, and certain material properties can decrease the qubit lifespan. This phenomenon, called quantum decoherence, is a critical obstacle to overcome to operate quantum processors.

Disentangling the architecture

The first step to reduce or eliminate quantum decoherence is to understand its root causes. SQMS Center scientists are studying a broadly used type of qubit called the transmon qubit. It is made of several layers of different materials with unique properties. Each layer, and each interface between these layers, play an important role in contributing to quantum decoherence. They create “traps” where microwave photons—key in storing and processing quantum information—can be absorbed and disappear.

Researchers cannot unequivocally distinguish where the traps are located or which of the various materials or interfaces are driving decoherence based on the measurement of the qubit alone. Scientists at the SQMS Center use uniquely sensitive tools to study these effects from the materials that make up the transmon qubits.

“We are disentangling the system to see how individual sub-components contribute to the decoherence of the qubits,” said Alexander Romanenko, Fermilab’s chief technology officer, head of the Applied Physics and Superconducting Technology Division and SQMS Center quantum technology thrust leader. “A few years ago, we realized that our [superconducting radio frequency] cavities could be tools to assess microwave losses of these materials with a preciseness of parts-per-billion and above.”

Measurements at cold temperatures

SQMS Center researchers have directly measured the loss tangent—a material’s ability to absorb electromagnetic energy—of high-resistivity silicon. These measurements were performed at temperatures only hundreds of a degree above absolute zero. These cold temperatures offer the right conditions for superconducting transmon qubits to operate.

“The main motivation for why we did this experiment was that there were no direct measurements on this loss tangent at such low temperatures,” said Mattia Checchin, SQMS Center scientist and the lead researcher on this project.

No material is perfect. Through rigorous testing and studies, researchers are building a more comprehensive understanding of the materials and properties best suited for quantum computing.

Checchin cooled a metallic niobium SRF cavity in a dilution refrigerator and filled it with a standing electromagnetic wave. After placing a sample of silicon inside the cavity, Checchin compared the time the wave dissipated without the silicon present to the time with it present. He found that the waves dissipated more than 100 times faster with the silicon present—from 100 milliseconds without silicon to less than a millisecond with it.

“The silicon dissipation we measured was an order of magnitude worse than the number widely reported in the [quantum information science] field,” said Anna Grassellino, director of the SQMS Center. “Our approach of disentangling the problem by studying each qubit sub-component with uniquely sensitive tools has shown that the contribution of the silicon substrate to decoherence of the transmon qubit is substantial.”

Re-evaluating silicon

Companies developing quantum computers based on quantum computing chips often use silicon as a substrate. SQMS Center studies highlight the importance of understanding which of silicon’s properties have negative effects. This research also helps define specifications for silicon that would ensure that substrates are useful. Another option is to substitute the silicon with sapphire or another less lossy material.

“Sapphire, in principle, is like a perfect insulator—so much better than silicon,” said Checchin. “Even sapphire has some losses at really low temperatures. In general, you would like to have a substrate that is lossless.”

Researchers often use the same techniques for fabricating silicon-based microelectronic devices to place qubits on silicon substrate. So sapphire has rarely been used for quantum computing.

“It has taken years of material science and device physics studies to develop the niobium material specifications that would ensure consistently high-performances in SRF cavities,” said Romanenko. “Similar studies need to be done for materials that comprise superconducting qubits. This effort includes researchers working together with the material industry vendors.”

Regardless of which material is used for qubits, eliminating losses and increasing coherence time is crucial to the success of quantum computing. No material is perfect. Through rigorous testing and studies, researchers are building a more comprehensive understanding of the materials and properties best suited for quantum computing.

This loss tangent measurement is a substantial step forward in the search for the best materials for quantum computing. SQMS Center scientists have isolated a problem and can now explore whether a more refined version of silicon or sapphire will harness the computational power of a qubit.

 

The Superconducting Quantum Materials and Systems Center is one of the five U.S. Department of Energy National Quantum Information Science Research Centers. Led by Fermi National Accelerator Laboratory, SQMS is a collaboration of 23 partner institutions—national labs, academia and industry—working together to bring transformational advances in the field of quantum information science. The center leverages Fermilab’s expertise in building complex particle accelerators to engineer multiqubit quantum processor platforms based on state-of-the-art qubits and superconducting technologies. Working hand in hand with embedded industry partners, SQMS will build a quantum computer and new quantum sensors at Fermilab, which will open unprecedented computational opportunities. For more information, please visit sqms.fnal.gov.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

 

The U.S. Department of Energy’s Fermi National Accelerator Laboratory welcomed Consul General Alan Gogbashian of the British Consulate in Chicago and leaders from United Kingdom Research and Innovation and the Science and Technology Facilities Council at a visit to Fermilab on Aug. 24. The visitors discussed with Fermilab management ongoing collaborative projects in particle accelerator and neutrino science and emerging collaborations in quantum information science. They also toured some of the lab’s research facilities.

The visitors were greeted by Fermilab Director Lia Merminga and members from the PIP-II and Long-Baseline Neutrino Facility projects, as well as Fermilab’s neutrino and quantum programs. The visit marked the first in-person meeting between STFC Executive Chair Mark Thomson and Merminga since her appointment to the position in April.

“The ongoing support and collaboration of UKRI and STFC with Fermilab is so important to advancing accelerator technologies and neutrino research for the benefit of the worldwide community,” said Merminga. “By working together and utilizing the strengths and expertise of all organizations, we are better positioned for science discoveries and applications in the future.”

STFC—one of UKRI’s research councils—funds U.K. research in areas including particle physics, nuclear physics, space science and astronomy. The visit presented an opportunity for the visitors to see the progress made by the Fermilab-led LBNF/DUNE neutrino project and learn more about the work on the construction of the PIP-II particle accelerator. STFC is a major contributor to both projects.

Stops on the tour included Fermilab’s work on superconducting radio frequency cavities for PIP-II, the high-power target experiment for LBNF/DUNE, the assembly of the near detector for the Short Baseline Neutrino Program and a visit to the Superconducting Quantum Materials and Systems Center at Fermilab. During the tours, the delegation also met with students from the U.K. institutions who enthusiastically shared their experience and their research in the neutrino experiment.

Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.