John Thomas, Fritz London Professor Emeritus, has won the Jesse W. Beams Award, given by the Southeastern Section of the American Physical Society for significant and meritorious research. The award was presented on October 21, 2011, at the conference banquet of the 78th Annual Meeting of SESAPS in Roanoke, Virginia. “It’s very exciting,” Thomas says, explaining that he was told that he won the award “for a combination of broad contributions to optical, molecular and atomic physics as well as my current work with atomic Fermi gases.” Thomas recently moved his program from Duke to North Carolina State University, where he is now a full professor. He is continuing his research into Fermi gases, using ultracold lithium-6 atoms that interact strongly when exposed to a magnetic field. Lithium-6 atoms belong to a class of particles called fermions that normally stay apart from each other, much like electrons in atoms, where two electrons cannot be in the same quantum state. But Thomas has figured out a way to make the atoms strongly interact at low temperature.
Thomas uses lasers to trap and cool the lithium-6 atoms to just a few billionths of a degree above absolute zero. Then he turns on a magnetic field. “The system is magnetically tunable,” he says. “We can make the fermions strongly attractive or strongly repulsive, by just changing the field.” It’s turned out to have far-reaching implications because, he says, “Most of nature is built of fermions that interact.” The strongly attractive lithium-6 atoms display some unusual behavior—such as perfect fluidity and strong spin-pairing—that is similar to unusual behavior seen in other exotic systems that interact strongly, such as quark-gluon plasma (QGP), neutron stars, and high-temperature superconductors. “This ultracold Fermi gas simulates most of physics,” he says. “So we’re able to do experiments to test theories in a lot of fields.” Thomas says when he first started working with lithium-6 in 1999, he didn’t foresee how important this cold gas would be as a model for other systems of interest to physicists. “It’s turned into a far richer field than we had imagined,” he says. According to the official SESAPS Beams Award citation, “Prof. John Thomas has been a leader in the field of atomic, molecular, and optical physics with his many ground-breaking experimental studies of trapped Fermi gases and their superfluidity. He has made an outstanding contribution to physics, in an opus of work on ultracold atomic fermions. This has led to a major discovery: the first evidence for a quantum gas in the unitary regime of scale-independent strong interactions. The cold diluted Fermi gas, first created by John Thomas's laboratory in 2002, has become a new paradigm for strongly interacting quantum fluids. His work has had a substantial impact in several areas of physics, from condensed matter physics, to nuclear physics and string theory, and has enormously contributed to the scientific development and visibility of the Southeastern region of the American Physical Society.” The Beams Award has been given every year since 1973. The award was named for Jesse Wakefield Beams, who spent most of his career at the University of Virginia, and whose many contributions to the field include constructing the first electron linear accelerator. Beams won the National Medal of Science in 1967. Five other Duke physicists have won the Jessie Beams Award: Professors Walter Gordy (1974), Larry Beidenharn (1979), Horst Meyer (1982), Ed Bilpuch (1992), and Berndt Mueller (2007). Thomas has no plans to slow down, and he continues to spend some time at Duke, while also teaching and doing research at N.C. State. He’s interested in starting a Center for Strongly Correlated Matter with Thomas Schaefer, a QGP theorist at N.C. State. The Center would focus on Fermi gases, QGP, superhot superconductors, and other systems in nature that interact strongly. He hopes the center would involve physicists from Duke, UNC and State. “I’m hopeful we can build new connections,” he says. “These Triangle-wide collaborations are very, very nice.” To read more detailed articles about Prof. Thomas’s research, click here and here.