Tony Leggett

John D. and Catherine T. MacArthur Professor Emeritus of Physics


Tony Leggett

Primary Research Area

  • Condensed Matter Physics


Sir Anthony J. Leggett, the John D. and Catherine T. MacArthur Professor and Center for Advanced Study Professor of Physics, has been a faculty member at Illinois since 1983. He is widely recognized as a world leader in the theory of low-temperature physics, and his pioneering work on superfluidity was recognized by the 2003 Nobel Prize in Physics. He is a member of the National Academy of Sciences, the American Philosophical Society, the American Academy of Arts and Sciences, the Russian Academy of Sciences (foreign member), and is a Fellow of the Royal Society (U.K.), the American Physical Society, and the American Institute of Physics. He is an Honorary Fellow of the Institute of Physics (U.K.). He was knighted (KBE) by Queen Elizabeth II in 2004 "for services to physics."

Professor Leggett has shaped the theoretical understanding of normal and superfluid helium liquids and other strongly coupled superfluids. He set directions for research in the quantum physics of macroscopic dissipative systems and use of condensed systems to test the foundations of quantum mechanics. His research interests lie mainly within the fields of theoretical condensed matter physics and the foundations of quantum mechanics. He has been particularly interested in the possibility of using special condensed-matter systems, such as Josephson devices, to test the validity of the extrapolation of the quantum formalism to the macroscopic level; this interest has led to a considerable amount of technical work on the application of quantum mechanics to collective variables and in particular on ways of incorporating dissipation into the calculations. He is also interested in the theory of superfluid liquid 3He, especially under extreme nonequilibrium conditions, in high-temperature superconductivity,in the low-temperature properties of glasses and in topological quantum computing,particularly in so-called "p+ip" Fermi superfluids.

Research Statement

Sir Anthony J. Leggett and Schroedinger's famous thought experiment Aspects of Cuprate Superconductivity
We are exploring a scenario for cuprate superconductivity in which a major factor is the reduction, due to increased screening by the Cooper pairs, of the long-wavelength, mid-infrared-frequency part of the Coulomb interaction. In addition, independently of this scenario, we are attempting to explain the c-axis transport properties of the cuprates and are looking at some problems associated with the "pseudogap" regime and with the peculiar features resulting from the existence of gap nodes.

Experimentally Oriented Studies of Basic Conceptual Issues in the Foundations of Quantum Mechanics
We are studying the application of the quantum-mechanical formalism to the description of various experiments that severely test one’s understanding of its meaning. In addition, we study possible alternative explanations of ostensibly relevant experiments in the literature.

Superfluidity and Phase Coherence in Very Degenerate Atomic Gases
Studies are being made of the superfluid density of an arbitrary many-body system, possible phase-coherence and interference experiments in Bose-condensed atomic gases, superfluidity in very degenerate dilute Fermi gases, and thermal transport in the ultralow-temperature regime of superfluid 3He.


  • Knighted, Order of the British Empire (KBE) "for services to physics" by Queen Elizabeth II, 2005
  • 2003 Nobel Prize in Physics (with V. L. Ginzburg and A. A. Abrikosov) "for pioneering contributions to the theory of superconductors and superfluids"
  • 2002/2003 Wolf Foundation Prize for research on condensed forms of matter (with B. I. Halperin)
  • 1999-Foreign Member, Russian Academy of Sciences
  • 1999-Eugene Feenberg Memorial Medal
  • 1998-Honorary Fellow, Institute of Physics, UK
  • 1997-Elected Foreign Associate, National Academy of Sciences
  • 1991-Paul Dirac Medal and Prize (British Institute of Physics) (The Eighth Simon Prize was awarded in 1976, the Tenth London Award in 1978, while the Maxwell Prize and Dirac prizes are annual).
  • 1985-Fellow of the American Physical Society (November 1985)
  • 1981-Ninth Simon Memorial Prize of the British Institute of Physics
  • 1981-Eleventh Fritz London Memorial Award
  • 1980-Fellow of the Royal Society
  • 1975-Maxwell Medal and Prize of the British Institute of Physics

Semesters Ranked Excellent Teacher by Students

Fall 2008PHYS 598
Fall 2003PHYS 498

Selected Articles in Journals

Books Authored or Co-Authored (Original Editions)

  • A.J. Leggett. Quantum Liquids: Bose condensation and Cooper pairing in condensed matter systems (Oxford University Press, 2006).
  • A. J. Leggett. The Problems of Physics. (Oxford University Press: Oxford & N.Y.). (1987). [German translation: Physik: Probleme, Themen, Fragen, (Birkhäuser Verlag, Basel, 1989); Japanese translation: Butsurigaku no Susume, Kinokuniya, Tokyo, 1990) Italian translation: I Problemi Della Fisica (Einaudi, Rome, 1991)] (electronic edition 2006).

Articles in Conference Proceedings

Related news

  • Events

Sir Anthony Leggett, winner of the 2003 Nobel Prize in Physics and the John D. and Catherine T. MacArthur Professor of Physics at the University of Illinois at Urbana Champaign, turned 80 years old on March 26. To celebrate, the Department of Physics is hosting a physics symposium in his honor, with participants coming from around the world. The symposium, “AJL@80: Challenges in Quantum Foundations, Condensed Matter Physics and Beyond,” is targeted for physicists and requires pre-registeration. It begins tonight, Thursday evening, and will go through Saturday evening (March 29 – 31, 2018).

In conjunction with the symposium, two public presentations will be offered back-to-back on Friday, March 30, starting at 7:30 p.m., at the I Hotel and Conference Center’s Illini Ballroom. (1900 S. First St., Champaign). There is no admission fee and registration is not required—all are welcome.

  • Research
  • Condensed Matter Physics

Experimenters have approximated the Leggett and Garg test. In 2011, White and colleagues demonstrated the extrastrong correlations in quantum optics, although in an average way and not with a single photon. Now, Joseph Formaggio, a neutrino physicist at the Massachusetts Institute of Technology in Cambridge, and colleagues provide a demonstration using data from the Main Injector Neutrino Oscillation Search (MINOS) experiment at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, which fires neutrinos at near-light-speed 735 kilometers to a 5.4-kiloton detector in the Soudan Mine in Minnesota.

  • Accolades
  • Condensed Matter Physics

Anthony Leggett, the John D. and Catherine T. MacArthur Professor of Physics at the University of Illinois, will be inducted into the 2015 Engineering at Illinois Hall of Fame tomorrow. He is among six selected for this distinction this year for significant achievements in leadership, entrepreneurship, and innovation of great impact to society.

The induction ceremony will take place on Friday, September 18, 2015, at 10 a.m. at the Beckman Institute for Advanced Science and Technology  (405 N Mathews Ave., Urbana). The ceremony is open to friends, family, and supporters, and Physics students and faculty are encouraged to attend.