Five Physicists at Penn State are Elected Fellows of the American Physical Society

Five physicists at Penn State have been elected Fellows of the American Physical Society (APS): John Collins, distinguished professor of physics; Vincent Crespi, professor of physics and of materials science and engineering; Paul Sommers, professor of physics and of astronomy and astrophysics; David Weiss, professor of physics; and Xiaoxing Xi, professor of physics and of materials science and engineering. The society is the largest physics organization in the world and publishes a wide range of research journals. The APS Fellowship Program recognizes members who have made advances in knowledge through original research and publication, have made significant and innovative contributions in the application of physics to science and technology, or who have made significant contributions to the teaching of physics or to service opportunities and activities of the society. Each year the society elects no more than one-half of one percent of its then-current membership to the status of Fellow in the American Physical Society.

John Collins

A theoretical physicist, John Collins was elected a Fellow for his seminal contributions to the foundation of the theory of strong nuclear interaction in elementary particles, known as quantum chromodynamics (QCD). He has played a vital role in formulating and proving many of the mathematical results that underlie QCD calculations. Without the aid of these results, it would not be possible to interpret experimental data produced by modern high-energy particle accelerators or to use the accelerators to search for new phenomena. The result is that these accelerators now can be used, in effect, as microscopes to probe fundamental physics at distance scales on the order of a hundredth or a thousandth the size of a proton.

Collins was recognized with a Penn State Faculty Scholar Medal in 2002 and a Humboldt Research Award for Senior Scientists in 2000. He was a scientific associate at the European Council for Nuclear Research (CERN) Particle Physics Laboratory on the French-Swiss border near Geneva, Switzerland in 1996 and 1997. He joined Penn State in 1990 as a professor of physics.

From 1980 to 1990, Collins worked at the Illinois Institute for Technology as an assistant professor, associate professor, and professor. From 1986 to 1987 he was a Guggenheim fellow. In 1985, he was named a member of the Institute for Advanced Study in Princeton, New Jersey. He was at Princeton University as an assistant professor from 1976 to 1980 and as a research associate from 1975 to 1976. He earned a bachelor's degree in mathematics at King's College in Cambridge, England in 1971 and a doctoral degree in theoretical physics at Cambridge University in 1975.

Vincent Crespi

Vincent Crespi was named a Fellow for his creative ideas and innovative computations that enhance understanding of nanoscale matter and that predict new structures and materials with properties possessing technological and/or fundamental scientific value. Crespi is a theoretical physicist whose research is aimed at developing a broad framework of knowledge in condensed-matter physics. He focuses on novel semiconductors, structural energies of materials, electron transport, and superconductivity. Among the applications he is interested in are novel carbon-tubule-based nanodevices that are one-billionth of a meter in size. He is studying their synthesis, mechanical properties, and electronic structures, including certain mechanical deformations that have a powerful influence on the semiconducting bandgap.

Crespi, who joined the Penn State faculty in the fall of 1997, has received other honors including a Penn State Faculty Scholar Medal in 2000, a National Science Foundation Faculty Early Career Development Award in 1999, a Packard Fellowship for Science and Engineering from the David and Lucile Packard Foundation in 1998, and a Research Innovation Award from the Research Corporation Foundation in 1999. He was a postdoctoral researcher and lecturer in graduate-level condensed-matter physics at the University of California at Berkeley from 1994 to 1995 and then a postdoctoral researcher at the Lawrence Berkeley Laboratory from 1995 to 1997. Crespi earned a bachelor's degree in physics at the Massachusetts Institute of Technology in 1988 and a doctoral degree in physics at the University of California at Berkeley in 1994.

Paul Sommers

Paul Sommers was elected a Fellow for his significant contributions to experimental cosmic-ray physics, for his major part in designing and building the Pierre Auger Cosmic Ray Observatory, and for his leadership role in using the observatory to obtain novel and important insights into the nature and properties of the highest-energy cosmic rays. The Pierre Auger Cosmic Observatory is an array of cosmic-ray detectors located in a remote part of Argentina. The observatory was built to decipher the messages carried by the highest-energy cosmic rays. These ultrahigh-energy cosmic rays offer a new window for observing extreme processes at work in the universe. Sommers also was an early advocate of combining air-fluorescence detectors with the instrument's giant surface-detector array. He led the team that developed the fluorescence detectors during the design and prototype phases of the observatory.

Prior to joining Penn State in 2005, Sommers was a research professor of physics at the University of Utah from 1993 to 2005 and a member of the scientific research staff there from 1982 to 1992. He was an assistant professor of mathematics at North Carolina State University from 1977 to 1980, and he was the Bahnson Postdoctoral Research Fellow at the University of North Carolina from 1975 to 1977. He also was a NATO postdoctoral fellow at Oxford University in the United Kingdom from 1973 to 1975. Sommers earned a bachelor's degree in physics at the University of California at Berkeley in 1968 and a master's degree in physics at the University of California at San Diego in 1969. He earned his doctoral degree at the University of Texas in 1973.

David Weiss

David Weiss was named a Fellow for his seminal contributions to laser cooling, precision measurements, the study of atoms in optical lattices, and for the experimental implementation of one-dimensional gases. Weiss's research involves experiments with laser-cooled atoms in optical lattices and other light traps. He uses cold, trapped atoms to make precise measurements of fundamental constants and to test fundamental symmetries. He also uses these atoms as model systems to address issues in atomic physics, condensed-matter physics, quantum mechanics, and statistical mechanics.

Weiss won a Penn State Faculty Scholar Medal for Physical Science in 2007, a Packard Fellowship for Science and Engineering in 1997, a Sloan Research Fellowship in 1997, and a National Science Foundation Faculty Early Career Development Award in 1996. He joined the faculty at Penn State in 2001 after having been an assistant professor at the University of California at Berkeley. Before that, he had been a postdoctoral fellow at École Normale Supérieure in Paris from 1993 to 1994. Weiss earned a bachelor's degree in physics at Amherst College, graduating summa cum laude, in 1985. He earned a doctoral degree in physics at Stanford University in 1993.

Xiaoxing Xi

Xiaoxing Xi was elected a Fellow for his extensive and seminal contributions to the science and applications of thin-film materials including high-temperature superconductors, ferroelectrics, and magnesium diboride. Xi's research concerns the materials physics underlying the applications of metal-oxide thin films; in particular, nanoscale-sized thin films. Xi focuses on understanding fundamental electrical, optical, and magnetic properties of these thin films and the effects on them of structural and interfacial defects. He uses the pulsed-laser deposition technique to fabricate oxide thin films and heterostructures. His research group developed a Hybrid Physical-Chemical Vapor Deposition (HPCVD) technique for epitaxial magnesium-diboride thin films.

Xi received a National Science Foundation Faculty Early Career Development Award in 1997 and the Kong-Chen Wong Science and Technology Award from the Chinese Academy of Science in 1997. He has been a visiting professor at Tsinghua University and Peking University, both in China. Prior to joining the faculty at Penn State in 1995, Xi was a member of the technical staff at Superconducting Core Technologies, Inc. He was a research scientist at the National Institute of Standards and Technology from 1993 to 1994 and was a research scientist at the University of Maryland from 1990 to 1995. From 1989 to 1990, Xi worked as a research associate at Rutgers University. He earned a bachelor's degree in physics at Peking University in 1982. He earned a Ph.D. degree in physics at Peking University and the Institute of Physics at the Chinese Academy of Science in 1987.

CONTACT

Barbara Kennedy (PIO): 814-863-4682, science@psu.edu