Historical Engineers: John Bardeen, Creator of the Transistor and Theory of Superconductivity
Awarded the Nobel Prize twice, John Bardeen is often recognized as one of the founders of the first transistor and the theory of superconductivity.
John Bardeen—one of history’s most significant engineers you might have never heard of—was one of only a few individuals awarded the Nobel Prize twice, and the first scientist to win two awards in physics.
Bardeen first won the Nobel Prize in 1956, sharing it with colleagues William Shockley and Walter Brattain, for the invention of the transistor.
Bell Labs scientists John Bardeen, William Shockley, and Walter Brattain. Image used courtesy of Nokia Bell Labs
He was then awarded it again in 1972, sharing it with Leon Cooper and John Schrieffer, for the theory of superconductivity—the phenomenon whereby charges move through a material without resistance.
Bardeen’s work can be said to have revolutionized the field of electrical engineering, paving the way for the dramatic technological advances we’ve seen through the decades, and still sits at its core even today.
Early Life and Education
Born in Wisconsin on May 23rd, 1908, Bardeen was the son of anatomy professor Charles Bardeen, who became the first dean of the medical school at the University of Wisconsin. It is from the same institution where Bardeen acquired his BS degree in electrical engineering in 1928 and an MS one year later.
Prior to graduating with his BS in 1928 at age 20 (after taking a year out to work in Chicago), Bardeen attended the University High School at Madison, graduating in 1923 at age 15. Widely recognized as a gifted student, it has been said that he could have graduated several years earlier, but that he postponed this due to his mother’s ill health and death, among other things.
Post-graduation and Professional Achievements
Bardeen eventually went on to work for Gulf Research Laboratories between 1930 and 1933, the research unit of the Gulf Oil Corporation of Pittsburgh. He worked as a geophysicist on the development of methods for interpreting magnetic and gravitational surveys. This work failed to keep him interested, however, and he eventually left it behind to enroll in a graduate program in mathematics and physics at Princeton University.
Working under Eugene Wigner, Bardeen wrote his thesis on a problem in solid-state physics. Prior to completing this, he was offered a position as a Junior Fellow of the Society of Fellows at Harvard University where he spent three years between 1935 and 1938, working on problems in electrical conduction and cohesion in metals. He was awarded his Ph.D. in mathematical physics in 1936.
For a period during the war, Bardeen led the group working on magnetic mines and torpedoes and mine and torpedo countermeasures at the Naval Ordinance Laboratory.
Contributions to Electrical Engineering
After the war, Bardeen joined the Bell Telephone Laboratories’ solid-state physics group. At the time, when people made long-distance telephone calls, the electrical signals carrying their voices would break down and turn into static if they weren’t amplified on their journey.
Vacuum tubes, an invention of the early 1900s, partially solved this problem by magnifying, reducing, or blocking electrical currents. While these made the first radios and television sets possible, they consumed lots of power, needed time to warm up, and would get very hot. They also had a tendency to break down.
Marvin Kelly, the director of Bell Labs, thought that a new, cheaper, and more efficient type of amplifier could be built from semiconductor crystals. While not much was known about them at the time, their intriguing properties had grabbed the interest of scientists worldwide, including Bardeen.
Inventing the Transistor
While working under William Shockley at Bell Labs, Bardeen was tasked with carrying out research on the electron-conducting properties of semiconductors along with Walter Brittain. Specifically, he was tasked with finding out why an amplifier designed by Shockley, which used a silicon crystal, didn’t work.
The first assembled transistor, called a "point contact transistor," produced amplification when two pointed metal contacts were applied to a semiconductor surface. Image used courtesy of Nokia Bell Labs
Using his knowledge of calculus and quantum mechanics, Bardeen discovered that electrons at the surface of a silicon crystal could form an electrical screen. His calculations proved that it was these surface states that stopped semiconductors from working as an amplifier.
Determined to find a workaround, the team came up and experimented with several designs. They scrapped Shockley’s initial design and developed mathematical models to come up with a semiconductor amplifier based on plastic, gold, and germanium. They would later call this a transistor.
The Theory of Superconductivity
In the 1950s, Bardeen continued research that he had started in the 1930s on superconductivity, as his Nobel Prize-winning research had already provided a theoretical explanation of why electrical resistance disappears in materials at temperatures nearing absolute zero.
The BCS theory of superconductivity (Bardeen-Cooper-Schrieffer) was advanced in 1957 and became the basis for all later theoretical works on the subject.
Bardeen later served as a professor of electrical engineering and physics at the University of Illinois, Urbana-Champaign between 1951 and 1975. He, Cooper, and Schrieffer were awarded the 1972 Nobel Prize in Physics for their jointly-developed theory of superconductivity.
Walter Brattain's notebook entry records from 1947 when the transistor effect was discovered. Image used courtesy of Nokia Bell Labs
Bardeen died in 1991 at the age of 82 from heart disease. He was survived by his wife, three children, and six grandchildren.
Today, transistors are found in every electronic device we rely on—from our phones to our televisions, radios, cars, medical equipment, data centers, trains, planes, and innumerable other applications. Further, the theory of superconductivity underpins many enduring principles in electrical engineering and even nuclear physics.
In about 1946 or 1947 (when I was 11 or 12) I attempted to spot-weld a cats’ whisker to the galena (lead sulfide) crystal in my crystal-set receiver, using a 1.5-volt A-cell battery, inadvertently creating a galena point- contact transistor, which gave a significant gain for about 15 seconds. I was unable to repeat the experiment, and was too naive to appreciate the implications of a solid-state amplifier. It might be noted that the field-effect transistor was patented in 1925.