John Bardeen was one of a handful of individuals awarded the Nobel Prize twice, and the first scientist to win dual awards in physics. Both times, he shared the prize with others. The first time his co-recipients were Walter Brattain and William Shockley, who worked with Bardeen on the invention of the transistor. The second time he shared the prize with Leon Cooper and Robert Schrieffer, with whom he developed the first generally accepted theory of low-temperature superconductivity.
Born on May 23, 1908 in Madison, Wisconsin, Bardeen became part of a well-educated and successful family. His father taught anatomy and later held the deanship at the University of Wisconsin Medical School. Before she married, his mother was a teacher at the Dewey Laboratory School in Chicago. Like his parents, Bardeen had a natural affinity for the sciences and proved an excellent student at a very young age. He jumped ahead in grades, completing high school early. At age 15, Bardeen was accepted into the engineering program at the University of Wisconsin, where he studied mathematics and physics in addition to his engineering coursework. In 1928, he earned an M.S. in electrical engineering in addition to a bachelorís degree.
Bardeen stayed on at the University of Wisconsin as a research assistant for two years before leaving to accept a position with Gulf Research Laboratories, located in Pennsylvania. Working for Gulf Oil, Bardeen began to realize that his primary interest lie in theoretical science rather than in its practical application. As a result, he enrolled at the University of Princeton and received a Ph.D. in mathematical physics in 1936. At Princeton, Bardeen became acquainted with Jane Maxwell while visiting friends. The couple married before Bardeen completed his graduate degree.
Bardeen embarked on a postdoctoral fellowship at Harvard University. Then, in 1938, he began teaching at the University of Wisconsin as an assistant professor. After outbreak of World War II, Bardeen requested a leave of absence from the university so that he could help with the American war effort as part of the Naval Ordnance Labs. He was invited to take part in the Manhattan Project, but declined. He considered returning to Wisconsin when the war ended, but ultimately decided to accept a position at Bell Laboratories in New Jersey. The Bell position promised to be not only more profitable for Bardeen, but also would allow him ample time to carry out research in solid-state physics, an area of keen interest to him.
At Bell, Bardeen became part of a new research group headed by William Shockley and that included William Brattain, whom Bardeen had met many years earlier through his brother. Bardeen and Brattain became not only good friends but excellent research partners. Bardeenís skills in analysis and theory made him a good fit to work with Brattain, who was especially adept at experimentation. The primary goal of their work was to develop a successful semiconductor amplification device. Similar efforts at Bell Labs had failed, but in late 1947 Bardeen and Brattain produced a device that worked, later referred to as the point-contact transistor. The transistor sparked the revolution of electronics. It eventually made the vacuum tube obsolete for most purposes and facilitated the production of increasingly smaller and smaller electronic devices.
The invention of the point-contact transistor was a great achievement, but there were problems for Bardeen at Bell Labs related to the question of who should receive credit for the invention. Technically, William Shockley was the supervisor of Bardeen and Brattain. Though he did not actively partake in the production of the first transistor, he felt he deserved co-recognition. Bardeen and Brattain, however, considered the achievement their own. The disagreement strained relations at the lab. As it turned out, only Bardeenís and Brattainís names appeared on the patent for the point-contact transistor. Still, Bardeen was unhappy continuing work in the research group. Eventually he left and began a professorship at the University of Illinois at Urbana-Champaign.
When he was not busy teaching, Bardeen carried out research, primarily into the phenomenon of superconductivity. Though the phenomenon had been discovered in 1911, it was still poorly understood at the time. Working with the postdoctoral researcher Leon Cooper and a graduate student, Robert Schrieffer, Bardeen developed the BCS theory (a moniker that bears the first letter of each of its developerís surnames) of superconductivity. According to the theory, electrons traveling through the crystal lattice of a superconductor cause the inward warping of that lattice and the production of phonons, packets of sound or vibratory energy. In turn, the phonons facilitate the coupling of electrons (phonon-mediated coupling), resulting in electron pairs (termed Cooper pairs). The theory goes on to explain how Cooper pairs are critical to the distinctive properties of superconductors. The BCS theory was very favorably received and has since been the cornerstone of almost all other theoretical work involving low-temperature superconductors.
Bardeen and his co-developers of the BCS theory received the Nobel Prize in Physics in 1972. By that time, Bardeen had already received the same award (in 1956) for his role in the invention of the transistor. Bardeen retired from the University of Illinois in 1975. He died on January 30, 1991, in Boston, Massachusetts.