John Bardeen (1908–1991) was an American physicist and the only person to win two Nobel Prizes in Physics. His theoretical understanding of semiconductors led to the transistor, and his later work on superconductivity was equally groundbreaking.
Bell Labs
Bardeen joined Bell Labs in 1945, where his theoretical insights were crucial to understanding why early transistor attempts failed. His understanding of surface states—how electrons behave at semiconductor surfaces—enabled the breakthrough.
The Transistor
On December 23, 1947, Bardeen and Brattain demonstrated the first working transistor. Bardeen’s theoretical framework explained how and why the device worked, transforming it from experiment to engineered technology.
First Nobel Prize
Bardeen shared the 1956 Nobel Prize in Physics with Shockley and Brattain for the transistor. He left Bell Labs soon after for the University of Illinois.
BCS Theory
At Illinois, Bardeen worked with Leon Cooper and J. Robert Schrieffer on the theory of superconductivity. Their BCS theory (named for their initials) explained how some materials lose all electrical resistance at low temperatures.
Second Nobel Prize
Bardeen, Cooper, and Schrieffer shared the 1972 Nobel Prize in Physics for BCS theory. This made Bardeen the only person to win two Nobel Prizes in Physics—one for enabling the digital age, one for explaining quantum phenomena.