John H(asbrouck) Van Vleck

Physicist, born in Middletown, Connecticut, USA. Educated entirely in the USA, he taught at Harvard (1922–3) and the University of Minnesota (1923–8), where he expanded (1926) English physicist Paul Dirac's quantum mechanics to explain the electric and magnetic properties of atoms. His classical treatise, The Theory of Electric and Magnetic Susceptibilities (1932), published while he was teaching at the University of Wisconsin (1928–34), earned him the title ‘father of modern magnetism’. He promoted the union of physics and chemistry, applying his discoveries to chemical bonding in crystals. Returning to Harvard (1934–69), he used his theory in studies of nuclear magnetic resonance and in the development of computer memory systems. He shared the 1977 Nobel Prize for Physics (with Philip Anderson and Nevill Mott) for his pioneering research. His colleagues knew him as a patient, gentle man whose personal interests included collecting detailed information of USA and European railroad timetables.

John Hasbrouck van Vleck (March 13, 1899 – October 27, 1980) was an American physicist. Van Vleck developed fundamental theories of the quantum mechanics of magnetism and the bonding in metal complexes (crystal field theory).

In the year 1961-62 he was George Eastman Visiting Professor in the University of Oxford and Professorial Fellow of Balliol College. For his contributions to the understanding of electrons in non-crystalline magnetic solids, van Vleck was awarded the 1977 Nobel Prize in Physics, along with Philip W.

Van Vleck transformations are also named after him.