Anthony James Leggett

Anthony James "Tony" Leggett

Sir Anthony James Leggett
Born March 26, 1938 (1938-03-26) (age 72)
Camberwell, London, England, UK
Residence United States
Citizenship Dual United Kingdom-United States
Fields Physicist
Institutions University of Sussex
University of Illinois at Urbana-Champaign
Alma mater Oxford University
Doctoral advisor Dirk ter Haar
Doctoral students Amir O. Caldeira
Known for Caldeira-Leggett model
Foundations of quantum mechanics
Superfluid phase of Helium-3
Quantum decoherence
Notable awards Maxwell Medal and Prize (1975)
Paul Dirac Medal (1992)
Nobel Prize in Physics (2003)
Wolf Prize in Physics (2002/03)

Sir Anthony James Leggett, KBE, FRS (born 26 March 1938, Camberwell, London, UK), aka Tony Leggett, has been a Professor of Physics at the University of Illinois at Urbana-Champaign since 1983.[1]

Professor Leggett 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.[2] He has shaped the theoretical understanding of normal and superfluid helium liquids and strongly coupled superfluids[3]. 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[4]. 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 non-equilibrium conditions, in high-temperature superconductivity, and in the newly realized system of Bose-condensed atomic gases.

Contents

Affiliations

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 (UK), the American Physical Society, and American Institute of Physics, and Life Fellow of the Institute of Physics.

Honours

He was awarded the 2003 Nobel Prize in Physics (with V. L. Ginzburg and A. A. Abrikosov) for pioneering contributions to the theory of superconductors and superfluids. 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". He also won the 2002/2003 Wolf Foundation Prize for research on condensed forms of matter (with B. I. Halperin). He was also honoured with the Eugene Feenberg Memorial Medal (1999). He was also elected as the Foreign Associate of the National Academy of Sciences in 1997. He was also made the Honorary Fellow of the Royal Society. He holds dual US/UK citizenship.

Currently

His current research focuses on cuprate superconductivity, conceptual issues in the foundations of quantum mechanics, superfluidity in highly degenerate atomic gases, and topological quantum computation.

The 29 December 2005 edition of the International Herald Tribune printed an article, "New tests of Einstein's 'spooky' reality", which referred to Leggett's Autumn 2005 debate at a conference in Berkeley, California, with fellow Nobel laureate Norman Ramsey of Harvard University.[5] Both debated the worth of attempts to change quantum theory. Leggett thought attempts were justified, Ramsey opposed. Leggett believes quantum mechanics may be incomplete because of the quantum measurement problem.He has been particularly interested in :

Aspects of Cuprate Superconductivity : He is 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, independent of this scenario, he is attempting to explain the c-axis transport properties of the cuprates and is 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 : He is 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, he is working on 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.

Early life

He was born in Camberwell, South London. His father's forebears were village cobblers in a small village in Hampshire, though his father broke with this tradition to become a greengrocer; his father would relate how he used to ride with him to buy vegetables at the Covent Garden market in London. His mother's parents were of Irish descent; her father had emigrated to England and worked as a clerk in the naval dockyard in Chatham .[6]. His maternal grandmother, who survived into her eighties, was sent out to domestic service at the age of twelve, she eventually married his grandfather and raised a large family, then in her late sixties emigrated to Australia to join her daughter and son-in-law, and finally returned to the UK for her last years.

His father and mother were each the first in their families to receive a university education; they met and became engaged while students at the Institute of Education at the University of London, but were unable to get married for some years because his father had to care for his own mother and siblings. His father worked as a secondary school teacher of physics, chemistry and mathematics. His mother also taught secondary school mathematics for a time, but had to give this up when he was born. He was eventually followed by two sisters, Clare and Judith, and two brothers, Terence and Paul. Their parents were both Roman Catholics, so the siblings were all brought up in that faith. He ceased to be a practicing Catholic in his early twenties.[6]

Soon after he was born, his parents bought a house in Upper Norwood, south London. However, when he was 18 months old, WWII broke out and he was evacuated to Englefield Green, a small village in Surrey on the edge of the great park of Windsor Castle, where he stayed for the duration of the war. After the end of the war, he returned to the Upper Norwood house and lived there until 1950; his father taught at a school in north-east London and his mother looked after the five children full time. He attended the local Catholic primary school, and later, following a successful performance in the "eleven plus" examination which he took rather earlier than most, transferred to the College of the Sacred Heart, Wimbledon.

Family

In the summer of 1972 he became engaged to Haruko Kinase, at that time an undergraduate student at Sussex, and they married in June 1972. In 1978, they had a daughter Asako.[6] His wife Haruko earned a Ph.D. in cultural anthropology from the University of Illinois at Urbana-Champaign and is currently doing research on the hospice system;[6]}. Their daughter, Asako, also graduated from UIUC, with a joint major in geography and chemistry.

Education

He won a scholarship to Balliol College, Oxford, in December 1954 and entered the University the following year with the intention of reading the degree technically known as Literae Humaniores (classics).

He completed a second undergraduate degree, this time in physics at Merton College. One person who was willing to overlook his unorthodox credentials was Dirk ter Haar, then a reader in theoretical physics and a fellow of Magdalen College, Oxford; so he signed up for research under his supervision. As with all Haar's students in that period, the tentatively assigned thesis topic was "Some Problems in the Theory of Many-Body Systems", which left a considerable degree of latitude.

Dirk took a great interest in the personal welfare of his students and their families, and was meticulous in making sure they received adequate support; indeed, he encouraged Leggett to apply for a Prize Fellowship at Magdalen. In the end Leggett's thesis consisted of studies of two somewhat disconnected problems in the general area of liquid helium, one on higher-order phonon interaction processes in superfluid 4He and the other on the properties of dilute solutions of 4He in normal liquid 3He (a system which unfortunately turned out to be much less experimentally accessible than the other side of the phase diagram, dilute solutions of 3He in 4He). Oxford University awarded Leggett an Honorary DLitt in June 2005.

Career

Leggett spent the period August 1964 - August 1965 as a postdoctoral fellow at the University of Illinois at Urbana-Champaign (UIUC), and David Pines and his colleagues (John Bardeen, Gordon Baym, Leo Kadanoff and others) provided a fertile environment. He then spent a year in the group of Professor Takeo Matsubara at Kyoto University in Japan.

After one more postdoctoral year which he spent in "roving" mode, spending time at Oxford, Harvard and Illinois, in the autumn of 1967 he took up a lectureship at the University of Sussex, where he was to spend the next fifteen years of his career.

In the spring of 1982 he accepted an offer from the University of Illinois at Urbana-Champaign (UIUC) of the MacArthur Chair with which the university had recently been endowed. As he had already committed himself to an eight-month stay at Cornell in early 1983, he finally arrived in Urbana in the early fall of that year, and has been there ever since.

Leggett's own research interests shifted away from superfluid 3He since around 1980; he worked inter alia on the low-temperature properties of glasses, high-temperature superconductivity, the BEC atomic gases and above all on the theory of experiments to test whether the formation of quantum mechanics will continue to describe the physical world as we push it up from the atomic level towards that of everyday life.

In 2007 he accepted a position at the University of Waterloo Canada. For the next five years, he will spend at least two months a year on campus at the Institute for Quantum Computing.

He currently serves as the chief scientist at the Institute for Condensed Matter Theory, a research institute hosted by the University of Illinois at Urbana-Champaign.

References

  1. "Anthony Leggett UIUC Faculty page". http://www.physics.uiuc.edu/people/Leggett/. 
  2. "Nobel Prize in Physics 2003.". http://nobelprize.org/nobel_prizes/physics/laureates/2003/. 
  3. A. J. Leggett. (1975). "A theoretical description of the new phases of liquid 3He.". Rev. Mod. Phys. 47: 331–414. doi:10.1103/RevModPhys.47.331. 
  4. A. O. Caldeira and A. J. Leggett. (1983). "Quantum tunneling in a dissipative system.". Ann. Phys. 149: 374–456. doi:10.1016/0003-4916(83)90202-6. http://www.icmt.illinois.edu/publications/leggett/1983AnnPhys-QuantumTunnellingInADissipativeSystem.pdf. 
  5. "New tests of Einstein's 'spooky' reality"
  6. 6.0 6.1 6.2 6.3 "Anthony J. Leggett – Autobiography". http://nobelprize.org/physics/laureates/2003/leggett-autobio.html.