David James Thouless FRS^[2][5] (/ˈθaʊlɛs/; 21 September 1934 – 6 April 2019^[6][7][8]) was a British condensed-matter physicist.^[9] He was the winner of the 1990 Wolf Prize and a laureate of the 2016 Nobel Prize for physics along with F. Duncan M. Haldane and J. Michael Kosterlitz for theoretical discoveries of topological phase transitions and topological phases of matter.^[10]

Born on 21 September 1934 in Bearsden, Scotland ^[11] to English parents, Priscilla (Gorton) Thouless, an English teacher, and Robert Thouless a psychologist and broadcaster.^[12] David Thouless was educated at St Faith's School then Winchester College and earned a Bachelor of Arts degree in Natural Sciences from the University of Cambridge as an undergraduate student of Trinity Hall, Cambridge.^[1] He obtained his PhD at Cornell University,^[6][13] where Hans Bethe was his doctoral advisor.^[4][14]

Thouless was a postdoctoral researcher at Lawrence Berkeley Laboratory, University of California, Berkeley, and also worked in the physics department from 1958 to 1959, giving a course on atomic physics.^[8][15][16] He was the first director of studies in physics at Churchill College, Cambridge, in 1961–1965, professor of mathematical physics at the University of Birmingham in the United Kingdom in 1965–1978,^[17] and professor of applied science at Yale University from 1979 to 1980,^[16] before becoming a professor of physics at the University of Washington^[18] in Seattle in 1980.^[17] Thouless made many theoretical contributions to the understanding of extended systems of atoms and electrons, and of nucleons.^[19][20][8] He also worked on superconductivity phenomena, properties of nuclear matter, and excited collective motions within nuclei.^[19][20][8]

Thouless made many important contributions to the theory of many-body problems.^[8] For atomic nuclei, he cleared up the concept of 'rearrangement energy' and derived an expression for the moment of inertia of deformed nuclei.^[8] In statistical mechanics, he contributed many ideas to the understanding of ordering, including the concept of 'topological ordering'.^[8] Other important results relate to localised electron states in disordered lattices.^[2][8]

Thouless married Margaret Elizabeth Scrase in 1958 and together they had three children.^[1] In 2016, Thouless was reported to be suffering from dementia.^[25] He died on 6 April 2019 in Cambridge, aged 84.^[7]

• Hofstadter's butterfly
• Single-electron transistor