Sir Anthony James Leggett is a world-renowned theoretical physicist whose pioneering work has fundamentally shaped the understanding of quantum phenomena in condensed matter systems. He currently serves as John D. and Catherine T. MacArthur Professor Emeritus of Physics at the University of Illinois Urbana-Champaign where he has been a faculty member since 1983 and chief scientist at the Institute for Condensed Matter Theory as of 2023. Born in London in 1938 Leggett initially pursued classical studies at Balliol College Oxford before shifting to physics at Merton College where he earned his undergraduate degree in 1961 and completed his DPhil in 1964. His early career included formative postdoctoral positions at the University of Illinois Urbana-Champaign under David Pines and colleagues including John Bardeen followed by research with Takeo Matsubara in Kyoto before joining the faculty at the University of Sussex where he rose to full professor by 1978.
Leggett's groundbreaking theoretical contributions have profoundly influenced the fields of superconductivity and superfluidity particularly through his work on the properties of superfluid helium-3 and other strongly coupled superfluid systems. His pivotal research established the theoretical framework for understanding the quantum behavior of macroscopic dissipative systems setting directions for decades of subsequent investigation and providing crucial insights into the quantum physics of condensed matter. Leggett's pioneering work on the theory of superconductors and superfluids earned him the Nobel Prize in Physics in 2003 recognizing his fundamental contributions to understanding quantum phenomena at macroscopic scales. His theoretical formulations continue to serve as essential references for experimental researchers exploring the quantum properties of matter at low temperatures with applications extending to contemporary research in topological quantum computing and the foundations of quantum mechanics.
Beyond his direct research contributions Leggett has been instrumental in advancing the field through his mentorship of numerous graduate students and postdoctoral researchers at the University of Illinois helping to train generations of theoretical physicists who continue to shape the discipline. He has maintained an active research program well into his emeritus years with ongoing investigations into the foundations of quantum mechanics and topological quantum computing particularly in p+ip Fermi superfluids. Leggett's leadership extends to his role as founding director of the Shanghai Center for Complex Physics established in 2013 demonstrating his continued influence in shaping international research directions. His commitment to exploring fundamental conceptual issues in quantum mechanics remains unwavering as he continues to investigate the application of quantum formalism to experiments that test the very foundations of our understanding of the quantum world.
