Born: 23 May 1908, Madison, WI, USA
Died: 30 January 1991, Boston, MA, USA
Affiliation at the time of the award: University of Illinois, Urbana, IL, USA
Prize motivation: "for their jointly developed theory of superconductivity, usually called the BCS-theory"
Prize share: 1/3
1956 Prize: Amplifying electric signals proved decisive for telephony and radio. First, electron tubes were used for this. To develop smaller and more effective amplifiers, however, it was hoped that semiconductors could be used - materials with properties between those of electrical conductors and insulators. Quantum mechanics gave new insight into the properties of these materials. In 1947 John Bardeen and Walter Brattain produced a semiconductor amplifier, which was further developed by William Shockley. The component was named a "transistor".
1972 Prize: When certain metals are cooled to extremely low temperatures, they become superconductors, conducting electrical current entirely without resistance. Based on quantum mechanics, John Bardeen, Leon Cooper, and Robert Schrieffer formulated a theory for the phenomenon in 1957. At extremely low temperatures, the interaction between electrons and atoms in the metals' crystalline structure causes the electrons to pair up with one another. As a result, their movement becomes orderly, unlike the random movement at normal temperatures, and electrical resistance disappears.