Date of Birth: 12/13/1923
Place of birth: Indianapolis
Citizenship: United States
After graduating from high school, Alexander enrolled at Harvard University and brilliantly graduated with a Bachelor of e Physics in 1943 because of the Second World War, he had to postpone graduate school, enrolling the senior non-commissioned officer in the US Navy. The next two years he worked at the Naval Research Laboratory in Washington (DC) as a radio engineer and engaged in designing antennas. At the end of the war, he returned to Harvard, where his supervisor was John X. Van Vleck.
In his master`s and doctoral theses. A. developed the application of quantum mechanics, trying to use it to explain the expansion of the spectral lines. Although it is generally accepted that this line corresponds to a single frequency, in fact, every line in the spectrum of a substance (specific, absorbed or emitted by the substance the frequency of light or other electromagnetic radiation) corresponds to a small frequency range. The width of the spectral line depends partly on intramolecular interactions. A. discovered that the newest mathematical methods of quantum field theory, which he studied under the direction of Julius C. Schwinger and others, can be used to explain how the expansion of the lines in the spectrum depends on the gas pressure. His results were among the first quantitative characteristics of the line width as a function of the intramolecular interactions. Some of its methodological approaches are widely used at present.
For this work A. received a master`s degree in 1947 and a doctorate in 1949. He was then admitted to the state laboratory technicians of the company "Bell", which was at that time one of the most advanced research centers in the field of solid state physics. Among the theorists involved in this field of physics in these laboratories were John Bardeen, Leon N. Cooper, Charles Kittel and William Shockley. Continuing to deal with the expansion of the spectral lines, AA also began to investigate the magnetic properties of solids under the direction of Charles Kittel. He was able to explain some of the properties of the insulating magnetic materials such as ferrites and antiferromagnetic oxides. Later, in 1961, at another via quantum model. A magnetic explained behavior of individual magnetic ions in nonmagnetic materials (for example, iron ions in aluminum).
This work revived interest in the phenomenon of A. superconductivity - the complete absence of electrical resistance in certain materials at very low temperatures. In 1957, Bardeen, Cooper, and John. Robert Schrieffer gave the first satisfactory theory of superconductivity (named for the initials of its creators, the BCS theory). In collaboration with other scientists from the laboratory of the company "Bell" A. held further theoretical and experimental studies in this direction, and as a result he was able to link the superconductivity with other properties of superconducting materials.
The effect of impurities in superconductors has long been a mystery: sometimes this influence was small, sometimes large. A. developed what he called "the theory of dirty superconductors," which is largely clarified the situation. Working with Pierre Morel, he predicted in 1960 that the superconducting liquid helium must exist anisotropic phase - liquid form, exhibiting different properties in different directions. Twelve years later, this phenomenon was confirmed experimentally Osheroffom Douglas and his colleagues in the laboratories of the company "Bell".
A. thereby contributed to the understanding of the flow without friction superfluidity was observed in liquid helium. In 1962, working with Dzh. M. Rowell, A. received laboratory confirmation of the Josephson effect ( "tunnel" of the electron percolation through the thin insulating barrier, predicted in 1962 by Brian D. Josephson). A. The final work on spontaneous symmetry breaking is often cited by experts on the physics of elementary particles.
During a guest lecturer at Tokyo University in 1953 ... 1954. A. seized remain on lifelong admiration for Japanese culture and passion for the game of Japanese. In that year, at the Kyoto International Conference on Theoretical Physics, he met with the British physicist Neville Mott, who invited him to the Cavendish Laboratory at Cambridge University, where between A. and Mott were frequent discussions about the behavior of electrons in amorphous (non-crystalline) bodies.
Almost all published before the work on solid state physics concerned crystalline solids, as a regular (lattice) arrangement of atoms in a crystal facilitates the mathematical solution to the problem, based on the quantum theory. A. showed that under certain conditions, the so-called free electrons in the amorphous body bind to certain special provisions - a phenomenon now known as Anderson localization. Although few scientists appreciated the importance of this work, Mott admitted that amorphous materials can be used as effective as a more structured system, which is more expensive production. A. Research on conduction, helped lay the foundations for the creation of amorphous semiconductors, which are used today in devices such as solar cells and photocopiers.
From 1967 to 1975, after Mott was able to organize a unique rate for the duration of a visiting professor, A. spent half of each year in Cambridge, and the other half - in the `Bell` laboratories. In 1974 he became deputy director of the laboratory, and the following year left his post in Cambridge to get a part-time job at Princeton University as a professor of physics.
A. Mott and Van Vleck shared the 1977 Nobel Prize in Physics "for his fundamental theoretical investigations of the electronic structure of magnetic and disordered systems." At the presentation of the winners. Per Olof Levdin, a member of the Royal Swedish Academy of Sciences, described the activity of atomic particles as the "dance of electrons responsible for electrical, magnetic and chemical properties of matter ... In his works, A" Mott and Van Vleck has shown that e-choreography is not only amazingly beautiful with scientific point of view, but also very important for the development of technology in our daily lives. "
In 1976, Alexander was appointed director of the consulting one of the laboratories of the company "Bell", namely the physical research laboratory in Murray Hill (New Jersey), and held that post until 1984 when he retired. In 1987, when there were some significant advances in the field of superconductivity, A. first of physicists published a theory that explains how some of the new materials can achieve a state of superconductivity at temperatures much higher than those used previously. A. According, there is no theoretical limit to achieve superconductivity even at room temperature.
A. continues to teach at Princeton, where he lives with his wife, Joyce, to Gosueyt marriage. They married in 1947, they have one daughter. At leisure, A. likes to tinker in the garden, hiking, as well as interested in the study of biology and Romanesque architecture.
In addition to the Nobel Prize, A. received the award on solid state physics Oliver Buckley, the American Physical Society (1964), Danny Heineman Prize Gottingen Academy of Sciences (1975), Guthrie medal of the London Institute of Physics (1978) and the National Medal `For his scientific achievements` of the National Science Foundation (1982). He is a member of the US National Academy of Sciences. American Academy of Arts and Sciences, the Japan Physical Society and the American Association of Basic Sciences.