Longtime Staff Member Lorraine DeSalvo Retires

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Category: Department News

Published: Friday, January 17 2020 05:56

After 41 years tending to the people and places of the Department of Physics, Director of Administrative Services Lorraine DeSalvo retired in December. In tribute, colleagues established the Lorraine DeSalvo Chair's Endowed Award for Outstanding Service to provide annual recognition to physics employees who demonstrate exemplary commitment to their work. 

DeSalvo graduated from the University of Maryland in 1972 and immediately accepted a job in the Department of Chemistry. 

“I have had the pleasure of knowing so many truly wonderful staff members on this campus during my years here,” she said. “Having this fund to recognize physics department colleagues is the finest farewell I could have asked for.” 

DeSalvo’s duties covered both facilities and human relations, meaning that she knew every inch of space and every employee. Her vast institutional memory and cross-campus contacts allowed her to untangle innumerable bureaucratic knots.  As Department Chair Steve Rolston noted, the most commonly uttered phrase in the department in recent decades may well have been, “Just ask Lorraine.” 

Modern, energy-intensive physics experiments long strained the aging infrastructure of the John S. Toll Physics Building and required constant vigilance and frequent, extensive renovations. When funding was approved for the new Physical Sciences Complex, DeSalvo’s workload expanded considerably. She worked with architects, builders, and capital improvement staff to plan the move, order furniture, and ensure that labs were built to the exacting specifications of dozens of extremely particular scientists. 

She fostered camaraderie with vibrant holiday parties and memorable fiestas, extending invitations to helpful colleagues across a swath of campus sectors. To the department’s many international students, scholars and visitors, she extended her welcome, wisdom and warmth. She owned a variety of small stuffed flamingos, which she dispatched to travelers with a request for a scenic photo. A slideshow of UMD physics folks hoisting pink birds across the globe ran continually in her office. 

She also displayed a keen regard for the department’s achievements. 

After the death of physicist Joe Weber in 2000, his lab fell into disuse. DeSalvo kept protective watch over the “Weber bars,” colossal aluminum cylinders built to record gravitational waves. Years later, in 2015, the LIGO experiment detected gravitational waves, generating worldwide acclaim and renewing interest in Weber’s quest. Last March, the Weber Garden was dedicated outside of the Physical Sciences Complex.  

“Without Lorraine’s protective instincts and her foresight that the Weber bars would prove significant, these excellent monuments to UMD innovation would have been lost forever to campus and the world,” Rolston said.

As a retiree, DeSalvo says she looks forward to finding the best crab cake restaurants around—and to keeping in touch with the department. 

She was serenaded at her retirement party by the following: 

Her global flamingos and holiday parties
And summer fiestas gave Physics some verve
And year in and year out, there surely could be no doubt
How heartfelt is her motto of “I live to serve.”

Contributions to the Lorraine DeSalvo Chair's Endowed Award for Outstanding Service can be made here.

Summer Camps Introduce High School Girls to Physics

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Category: Department News

Published: Friday, January 17 2020 05:56

Since its inception in 1988, over 1,500 students have participated in the University of Maryland’s Summer Girls physics program for rising 9th through 12th graders. Last summer alone, more than 50 young students came to campus for one or two weeks to explore concepts from classical and modern physics, conduct hands-on laboratory experiments, and learn about careers in physics. The students also met and spoke with physics professors and graduate students, listened to interesting lectures, and toured research laboratory tours. 

The program is mostly funded by a grant from the National Science Foundation through the Physics Frontier Center at the Joint Quantum Institute. Students paid only $25 to participate last year. Participants of the program, which is directed by Donna Hammer, have come not only from Maryland, Virginia and Washington, D.C., but also from Pennsylvania, New Jersey and all over the world. Graduates have gone on to become engineers, doctors, computer scientists and, of course, physicists. 

Johnpierre Paglione Receives $1.55M from the Moore Foundation

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Category: Research News

Published: Friday, January 17 2020 05:56

Physics Professor Johnpierre Paglione has been awarded more than $1.5 million by the Gordon and Betty Moore Foundation to study the complex behavior of electrons in quantum materials.Johnpierre Paglione

“The Moore Foundation has played a pivotal role in supporting and promoting quantum materials research over the last five years, and I am extremely excited to continue to be part of this effort,” said Paglione, who also directs UMD’s Quantum Materials Center (formerly the Center for Nanophysics and Advanced Materials).

The new grant was awarded by the Moore Foundation’s Emergent Phenomena in Quantum Systems (EPiQS) initiative, a quantum materials research program that funds work on materials synthesis, experiments, and theory, with an interdisciplinary approach that includes physicists, chemists, and materials scientists. EPiQS focuses on exploratory research that develop deep questions about the organizing principles of complex quantum matter, and it also supports progress toward new applications, like quantum computing and precision measurement. 

Paglione’s award for materials synthesis was one of only 13 in the U.S. and renews an earlier grant he received from EPiQS, which has provided more than $120 million to researchers since 2013.

“Fundamental studies of quantum materials play a critical role in not only supporting current development of quantum technologies, but also the discovery of new phenomena that hold promise for future applications,” Paglione said.

In recognition of that critical role, UMD’s Center for Nanophysics and Advanced Materials was renamed to the Quantum Materials Center (QMC) in October. The change emphasized the evolving interests of the Center’s members, and it was announced at a one-day symposium in September organized by Paglione and several colleagues.

“Our center’s purpose will remain focused on the fundamental exploration and development of advanced materials and devices using multidisciplinary expertise drawn from the physics, chemistry, engineering and materials science departments,” Paglione said. “But we will place strong emphasis on the pursuit of optimized and novel quantum phenomena with potential to nucleate future computing, information and energy technologies.”

The symposium brought together many local scientists who study quantum materials, including researchers from the university’s Departments of Physics, Chemistry and Biochemistry, Electrical and Computer Engineering, and Materials Science and Engineering, in addition to researchers from the National Institute of Standards and Technology (NIST) and the Laboratory for Physical Sciences. Amitabh Varshney, dean of UMD’s College of Computer, Mathematical, and Natural Sciences, and Robert Briber, associate dean of UMD’s A. James Clark School of Engineering, attended and shared their perspectives on campus initiatives in quantum science, including the newly formed Quantum Technology Center.

That meeting was bookended by several exciting research results from Paglione and his colleagues in the QMC. In June, they reported capturing the best evidence yet of Klein tunneling, a quantum quirk that allows electrons to burrow through a barrier like it’s not even there. The result, which was featured on the cover of the journal Nature, arises from a duo of quantum effects at the junction of two materials. One is superconductivity, which keeps electrons paired off in highly correlated ways. The other has to do with the precise kind of superconductivity present—in this case, topological superconductivity that further constrains the way that electrons interact with the interface between the two materials. In a nutshell, electrons heading toward the junction aren’t allowed to reflect back, which leads to their perfect transmission.

In August, Paglione and his collaborators published a paper in the journal Science about a new, unconventional superconductor. That material—uranium ditelluride—may also exhibit some effects expected of a topological superconductor, including a demonstrated resilience to magnetic fields that typically destroy superconductivity. One of the paper’s co-authors, NIST scientist and Adjunct Associate Professor of Physics Nicholas Butch, called the material a potential “silicon of the quantum information age,” due to its stability and potential use as a storage medium for the basic units of information in quantum computers.

In a follow-up paper published in the journal Nature Physics in October, many of the same researchers teamed up with scientists from the National High Magnetic Field Laboratory to test the properties of uranium ditelluride under extreme magnetic fields. They observed a rare phenomenon called re-entrant superconductivity, furthering the case that uranium ditelluride is not only a profoundly exotic superconductor, but also a promising material for technological applications. Nicknamed “Lazarus superconductivity” after the biblical figure who rose from the dead, the phenomenon occurs when a superconducting state arises, breaks down, then re-emerges in a material due to a change in a specific parameter—in this case, the application of a very strong magnetic field.

“This is indeed a remarkable material and it’s keeping us very busy,” Paglione said. “Uranium ditelluride may very well become the ‘textbook’ spin-triplet superconductor that people have been seeking for dozens of years and, more importantly, may be the first manifestation of a true intrinsic topological superconductor with potential for all sorts of technologies to come!”

Written by Chris Cesare with contributions from Matthew Wright

A Physics Career Along the Path Less Traveled

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Category: Department News

Published: Friday, January 17 2020 05:56

Michelle Girvan’s career defies easy categorization. Currently a professor of physics at the University of Maryland, very little of her research would be immediately recognizable to a physics traditionalist. Instead, she applies her physics training to tackle discipline-spanning scientific questions that range from social relationships and cancer genetics to artificial intelligence (AI). 

When asked how she identifies herself to new colleagues, a thoughtful smile crossed her face as she pondered a reply.Michelle Girvan

“That’s a very interesting question. I often say I’m a physics professor who does applied mathematics. It’s a broader umbrella that allows me to work on nearly any problem, as long as I focus on the math that underlies it,” explained Girvan, who also has joint appointments in UMD’s Institute for Physical Science and Technology and Institute for Research in Electronics and Applied Physics. “But I still think of myself as a physicist, because physicists seek simple, cohesive explanations for complex phenomena. I’m still looking for those overarching organizing principles, even if I’m applying them to biological or social problems.”

Girvan is quick to point out that, while her approach may be nontraditional, she’s far from alone. She notes a recent meeting of the American Physical Society that featured sessions on neural networks, gene regulation and econophysics—a relatively new field that applies physical theories and methodologies to the study of economics. The common thread among these scientists, Girvan said, is that they tackle their research by first asking, “How would a physicist solve this problem?”

“I think we need more of that,” Girvan added. “A physicist’s perspective might help identify patterns and phenomena that can go unnoticed by others who focus on fine-scale details.”

Girvan’s unorthodox path began during her undergraduate studies in physics and math at the Massachusetts Institute of Technology, where a course in the Department of Earth, Atmospheric and Planetary Sciences first introduced her to the concepts of chaos, nonlinear dynamics and complexity. From there, she went to Cornell University to pursue her Ph.D. with applied mathematician Steven Strogatz, then on to a postdoctoral fellowship at the Santa Fe Institute, where she now holds an external faculty position. 

During her first stint at the Santa Fe Institute, she co-developed the well-known Girvan-Newman algorithm in collaboration with Mark Newman, now at the University of Michigan. They published their work in the Proceedings of the National Academy of Sciences in 2002. Broadly stated, the algorithm helps to identify relationships, connections and groupings in networks that might not be readily apparent. 

“If you were to apply the algorithm to a social media network, for example, you might logically expect to find people divided into strong social or professional groups. Among scientists, you’d expect physicists to be grouped with other physicists, biologists with biologists, and so on,” Girvan said. “Our algorithm can also help identify interesting deviations from these expected norms.”  

The Girvan-Newman algorithm can also be applied to the recommendation systems used by online retailers and streaming entertainment services like Netflix and Spotify, Girvan noted. 

“If you link two movies together, in terms of the frequency they’re watched by the same person, the algorithm can uncover groupings that might not be obvious,” Girvan said. “Action movie fans interested in science fiction might also like a third kind of movie you wouldn’t expect.”

Girvan joined UMD in 2007, drawn in no small part by the university’s strong tradition in nonlinear dynamics. She has collaborated frequently with many researchers across campus, including two world-renowned experts: Distinguished University Professors Edward Ott and James Yorke, both well known for their landmark publications in chaos theory and other aspects of nonlinear dynamics. 

Here at UMD, Girvan has applied the tools and philosophical framework of physics to investigate questions in ecology, genetics, development, cancer biology, neuroscience, social networks, machine learning and more. At the moment, she is highly interested in the interface between the human brain and artificial neural networks. 

“Living in this age of rapid advancements in AI, I want to know how our understanding of the human brain, at an abstract level, can help us develop more effective AI methodologies,” Girvan said. 

Girvan is also pursuing approaches for integrating knowledge-based models derived from physics with knowledge-free AI models. 

“So many successes in AI and machine learning have come from ‘black box’ approaches—you throw a lot of data at an AI system and it learns how to make predictions. But these black-box models don’t help us understand the natural world any better,” Girvan said. “By incorporating what we already know about the underlying physics, we can build hybrid systems that combine knowledge-based approaches and knowledge-free approaches, enabling more accurate predictions that also give us new insights into how the world works.” 

Girvan also has a strong interest in training the next generation of discipline-defying researchers. She currently serves as the principal investigator for COMBINE: Computation and Mathematics for Biological Networks, UMD’s National Science Foundation (NSF)-funded Research Traineeship (NRT) program in network biology. The program immerses graduate students in research and training that integrates tools from physics, mathematics and computer science to gain deeper insights into the principles that govern living systems. 

“We’re interested in students who want to solve life science problems where network structure matters, from neurological to ecological networks,” Girvan said. “We brought in a diverse group of faculty from a wide range of disciplines to help with the effort. We have about two and a half years of NSF funding left, so we’re looking into other ways to keep it going.”

While her career path as a physicist may play fast and loose with tradition, Girvan isn’t opposed to all time-honored conventions. In her free time, she participates in one of the oldest sporting endeavors known: equestrian competition. 

“I have some of my best thoughts after I’m done riding,” Girvan mused. “I feel like it takes me out of the local landscape where I’m stuck on the small problems and clears any blockages I might have in my head.”

Written by Matthew Wright

Listen to Michelle Girvan discuss how artificial intelligence can help predict chaotic behavior.