- Category: Research News
- Published: Friday, August 23 2019 10:02
The center will capitalize on the university’s strong research programs and partnerships in quantum science and systems engineering, and pursue collaborations with industry and government labs to help take promising quantum advances from the lab to the marketplace. QTC will also train students in the development and application of quantum technologies to produce a workforce educated in quantum-related engineering.
The new center is a collaboration between UMD’s Department of Physics in the College of Computer, Mathematical, and Natural Sciences (CMNS) and UMD’s Department of Electrical and Computer Engineering in the A. James Clark School of Engineering.
"The Quantum Technology Center will add to the University of Maryland’s world-renowned leadership in the quantum fields, including physics, engineering, computer science, and materials research," said Laurie Locascio, vice president for research at UMD. "This new center will build on these strengths to develop future quantum technology and new applications, and to train students and researchers in quantum technology."
The announcement comes at a pivotal time when quantum science research is expanding beyond physics into materials science, engineering, computer science, chemistry and biology. Scientists across these disciplines are looking for ways to exploit quantum physics to build powerful computers, develop secure communication networks, and improve sensing and imaging capabilities. In the future, quantum technology could also impact fields such as artificial intelligence, energy and medicine.
The director of QTC will be Ronald Walsworth, who recently joined UMD after serving on the faculty at Harvard University and as a senior physicist at the Smithsonian Astrophysical Observatory.
“We are thrilled that Dr. Ronald Walsworth has chosen the University of Maryland and our commitment to accelerating quantum research and discovery,” said Darryll J. Pines, dean of the A. James Clark School of Engineering and Farvardin Professor. “As a signature senior hire for Maryland and as the inaugural director of the Quantum Technology Center, Dr. Walsworth brings a critical expertise in quantum sensing, measurement, and instrumentation to College Park.”
Walsworth is an expert in utilizing quantum physics to develop advanced measurement tools for medicine, planetary science and fundamental physics. He holds several patents on a quantum sensing technology that uses an optically active defect in diamond to probe tiny changes in electromagnetic fields and temperature.
Walsworth’s lab spun off two startups that apply quantum sensing technology to biomedical diagnostics, and he has served as a scientific advisor for several technology companies including Quantum Diamond Technologies Inc., Butterfly Network, Quantum-Si and Hyperfine Research.
He is also a fellow of the American Physical Society and received its 2005 Francis M. Pipkin Award for his work in developing and applying precision measurement tools. Walsworth received his bachelor’s degree in physics from Duke University in 1984 and his Ph.D. in physics from Harvard University in 1991.
“I am excited to join the strong quantum community at the University of Maryland and work together to make QTC a world leader in quantum technology development, translation, and education,” said Walsworth, who joined UMD for Fall 2019 as the Minta Martin Professor in the Department of Electrical and Computer Engineering with a joint appointment in the Department of Physics.
QTC will initially draw members from the Departments of Electrical and Computer Engineering, Physics, and Computer Science. New faculty members have also been hired, including Electrical and Computer Engineering Assistant Professor Cheng Gong and Physics Assistant Professors Alicia Kollár and Norbert Linke.
“We are proud to work with our colleagues in engineering to jointly establish the Quantum Technology Center,” said Amitabh Varshney, dean of CMNS. “QTC will enable the rapid development of quantum technologies through high-impact research that spans sensors, secure communication, and advanced computation.”
QTC will have laboratory space in the Jeong H. Kim Engineering Building, the Physical Sciences Complex, and the Clark School’s new E.A. Fernandez IDEA (Innovate, Design and Engineer for America) Factory, which is dedicated to creative innovation and entrepreneurship by students and faculty and is expected to open in 2021. The center will be administered through UMD’s Institute for Research in Electronics and Applied Physics.
The new center will add to the university’s world-renowned leadership in the quantum fields, which includes being ranked No. 6 in quantum and atomic physics by U.S. News & World Report. UMD is also home to two quantum research partnerships with the National Institute of Standards and Technology—the Joint Quantum Institute and the Joint Center for Quantum Information and Computer Science—as well as a research collaboration with the Army Research Laboratory.
In addition, UMD quantum faculty members are also entrepreneurs. The quantum computing startup IonQ, which aims to bring general-purpose quantum computers to market, was co-founded by UMD Distinguished University Professor Christopher Monroe.
Original posting: https://cmns.umd.edu/news-events/features/4480
About the College of Computer, Mathematical, and Natural Sciences
The College of Computer, Mathematical, and Natural Sciences at the University of Maryland educates more than 9,000 future scientific leaders in its undergraduate and graduate programs each year. The college’s 10 departments and more than a dozen interdisciplinary research centers foster scientific discovery with annual sponsored research funding exceeding $175 million.
Everything radiates. Whether it's a car door, a pair of shoes or the cover of a book, anything hotter than absolute zero (i.e., pretty much everything) is constantly shedding radiation in the form of photons, the quantum particles of light.
A twin process—absorption—is usually also present. As photons carry away energy, passers-by from the environment can be absorbed to replenish it. When absorption and emission occur at the same rate, scientists say that an object is in equilibrium with its environment. This often means that object and environment share the same temperature.
Far away from equilibrium, new behaviors can emerge. In a paper published August 1, 2019 as an Editors’ Suggestion in the journal Physical Review Letters, scientists at JQI and Michigan State University suggest that certain materials may experience a spontaneous twisting force if they are hotter than their surroundings.
"The fact that a material might feel a torque due to a temperature difference with the environment is very unusual," says lead author Mohammad Maghrebi, a former JQI postdoctoral researcher who is now an assistant professor at Michigan State University.
The effect, which hasn't yet been observed in an experiment, is predicted to arise in a thin ribbon of a material called a topological insulator (TI)—something that allows electrical current to flow on its surface but not through its innards.
In this case, the researchers made two additional assumptions about the TI. One is that it is hotter than its environment. And another is that the TI has some magnetic impurities that affect the behavior of electrons on its surface.
These magnetic impurities interact with a quantum property of the electrons called spin. Spin is part of the basic character of an electron, much like electric charge, and it describes the particle’s intrinsic angular momentum—the tendency of an object to continue rotating. Photons, too, can carry angular momentum.
Although electrons don’t physically rotate, they can still gain and lose angular momentum, albeit only in discrete chunks. Each electron has two spin values—up and down—and the magnetic impurities ensure that one value sits at a higher energy than the other. In the presence of these impurities, electrons can flip their spin from up to down and vice versa by emitting or absorbing a photon that carries the right amount of energy and angular momentum.
Maghrebi and two colleagues, JQI Fellows Jay Deep Sau and Alexey Gorshkov, showed that radiation emanating from this kind of TI carries angular momentum skewed in one rotational direction, like a corkscrew that twists clockwise. The material gets left with a deficit of angular momentum, causing it to feel a torque in the opposite direction (in this example, counterclockwise).
The authors say that TIs are ideal for spotting this effect because they play host to the right kind of interaction between electrons and light. TIs already link electron spin with the momentum of their motion, and it's through this motion that electrons in the material ordinarily absorb and emit light.
If an electron on the surface of this particular kind of TI starts with its spin pointing up, it can shed energy and angular momentum by changing its spin from up to down and emitting a photon. Since the TI is hotter than its environment, electrons will flip from up to down more often than the reverse. That’s because the environment has a lower temperature and lacks the energy to replace the radiation coming from the TI. The result of this imbalance is a torque on the thin TI sample, driven by the random emission of radiation.
Future experiments might observe the effect in one of two ways, the authors say. The most likely method is indirect, requiring experimenters to heat up a TI by running a current through it and collecting the emitted light. By measuring the average angular momentum of the radiation, an experiment might detect the asymmetry and confirm one consequence of the new prediction.
A more direct—and likely more difficult—observation would involve actually measuring the torque on the thin film by looking for tiny rotations. Maghrebi says that he's brought up the idea to several experimentalists. "They were not horrified by having to measure something like a torque, but, at the same time, I think it really depends on the setup," he says. "It certainly didn't sound like it was impossible."
Story by Chris Cesare: https://jqi.umd.edu/news/corkscrew-photons-may-leave-behind-spontaneous-twist