| Fritz Wolfgang London |
| Born |
March 7, 1900
Breslau, Germany |
| Died |
March 30, 1954
Durham, North Carolina
|
| Residence |
USA |
| Citizenship |
German, later USA |
| Field |
Theoretical Physics |
| Institutions |
University of Berlin
University of Oxford
College de France
Duke University |
| Known for |
work on quantum theory |
| Notable prizes |
Lorentz Medal, 1953 |
Fritz Wolfgang London (March 7, 1900–March 30, 1954) was a German-born
American theoretical physicist. London's early work
with Heitler [1] on
chemical bonding is now treated in any textbook on physical chemistry. This paper was the first to properly explain the bonding
in a homonuclear molecule as H2. It is no coincidence that the Heitler-London work appeared shortly after the
introduction of quantum mechanics by Heisenberg and Schrödinger, because quantum mechanics was crucial in their explanation of the covalent bond. Another
necessary ingredient was the realization that electrons are indistinguishable, as expressed in the Pauli principle.
Other early work of London was in the area of intermolecular forces. He coined
the expression "dispersion effect" for the attraction between two rare gas atoms at large (say about 10 Å) distance from each
other. Nowadays this attraction is often referred to as "London force". In 1930 he gave (together with R. Eisenschitz)[2] a unified treatment of the interaction between two noble gas
atoms that attract each other at large distance, but at short distance are repellent. Eisenschitz and London showed that this
repulsion is a consequence of enforcing the electronic wavefunction to be antisymmetric under electron permutations. This
antisymmetry is required by the Pauli principle and the fact that electrons are fermions.
For atoms and nonpolar molecules, the London dispersion force is the only
intermolecular forces and are responsible for the existence of the liquid and solid states. For polar molecules, this force is one part of the van
der Waals force, along with forces between the permanent molecular dipole moments.
London was the first theoretical physicist to make the fundamental, and at the time controversial, suggestion that
superfluidity is intrinsically related to the Einstein condensation of bosons, a phenomenon now known as
Bose–Einstein condensation (BEC). However, note
that Bose, whose contribution was to recognize that the statistics of massless photons could also
be applied to massive particles, did not contribute to the theory of the condensation of bosons.
London was also one of the early authors (including Schrödinger) to have properly
understood the principle of local gauge invariance (Weyl) in the context of the then new
quantum mechanics.
London was born in Breslau (now Wrocław), then in Germany but now in Poland. After Hitler's Nazi Party passed the 1933 racial
laws, London lost his position at the University of Berlin. He took
visiting positions in England and France, and eventually emigrated to the United States in
1939. In 1945, he became a naturalized citizen. He died in Durham, North Carolina.
London was in his later life a professor at Duke University. He was awarded the
Lorentz Medal in 1953.
Bibliography
- Gavroglu, Kostas Fritz London: A Scientific Biography (Cambridge, 2005)
References
- ^ W. Heitler and F. London, Zeitschrift für Physik, vol. 44, p. 455 (1927).
English translation in H. Hettema, Quantum Chemistry, Classic Scientific Papers, World Scientific, Singapore (2000).
- ^ R. Eisenschitz and F. London, Zeitschrift für Physik, vol. 60, p. 491
(1930). English translation in H. Hettema, Quantum Chemistry, Classic Scientific Papers, World Scientific, Singapore (2000).
Fritz London: A Scientific Biography , by Kostas Gavroglu, Cambridge University Press (1995). ISBN: 0521432731.
External links
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