(b. Madison, Wisconsin, 23 May 1908; d. Boston, Massachusetts, 30 January 1991)
condensed-matter physics, superconductors, superconductivity, many-body theory, transistor.
Bardeen worked on developing the quantum mechanical theory of solids throughout his entire physics career. He was among the handful of American physicists who first applied this theory to real (rather than ideal) materials. He was the first person ever to win two Nobel Prizes in the same field—the first, in 1956 with Walter Brattain and William Shockley for the invention of the transistor; the second, in 1972 with Leon Cooper and J. Robert Schrieffer for the theory of superconductivity.
Early Years. Bardeen’s highly educated family, whose American roots trace back to the Plymouth Colony, placed a strong value on frugality, hard work, learning, and service to society and nation. His grandfather Charles William Bardeen, who had enlisted as an abolitionist in the Civil War at age fourteen, established School Bulletin Publications, in which for fifty years he expressed his progressive views on quality education. John Bardeen’s father Charles Russell Bardeen, a graduate in the first class of the Johns Hopkins University medical school, founded and served as dean of the University of Wisconsin’s medical school. John’s mother Althea Harmer had studied art in New York and Chicago and taught home economics at the University of Chicago’s progressive laboratory high school established by John Dewey. At the time she met and married Charles Russell, she ran a small interior decorating business in Chicago. John Bardeen and all his siblings, his older brother William, his younger brother Thomas, his younger sister Helen, and his even younger half-sister Ann, grew up in Madison.
To keep John from being bored in school, Althea had him skipped so often that he finished eighth grade before he was nine. At that age he entered the University of Wisconsin’s University High School, whose progressive philosophy resembled that of the Dewey School, where Althea had taught. Charles Russell encouraged John’s science education by working mathematics problems with him during the great flu epidemic of 1918 and by purchasing organic dyes and other chemicals for him to experiment with in his basement laboratory. An unusually quiet boy, John relied on his extroverted older brother Bill to help him communicate. He would recreate this pattern in later years with a few of his closest friends and colleagues, including his wife Jane, his Bell Laboratories partner Walter Brattain, and his first graduate student, Nick Holonyak.
In April 1920, when John was not yet twelve, Althea died of breast cancer. Less than six months later, Charles Russell married his secretary, Ruth Hames. John nevertheless completed his University High coursework by age thirteen. Given his youth, he postponed entering the freshman class at the University of Wisconsin for two years, taking extra courses, mainly in mathematics, at Madison Central High School.
Training and First Positions. At the University of Wisconsin Bardeen majored in electrical engineering. He responded with excitement to quantum mechanics, as presented by John Van Vleck in his Wisconsin course on quantum physics and in Van Vleck’s research seminar, but Bardeen was not yet ready to become a physicist. The engineer Leo J. Peters supervised Bardeen’s master’s thesis on electrical prospecting for oil. When Peters left
Wisconsin to take a position at Gulf Research Laboratories in Pittsburgh, Bardeen worked on a problem in antenna theory, which did not inspire him. In 1930, he followed Peters to Gulf Labs and returned to the geophysics of electromagnetic prospecting. Although Bardeen initially enjoyed his work at Gulf, geophysics never fully captured his interest. He so much enjoyed participating in a research seminar in modern physics at the University of Pittsburgh that in the Depression year of 1933 he gave up his secure position at Gulf to enter Princeton’s graduate program in mathematics. The night before he left Pittsburgh he met Jane Maxwell, his future wife. Their courtship would solidify over the next five years and result in a marriage of fifty-three years.
Bardeen’s Princeton studies laid the foundation for his career in physics. Following the example of his friend Frederick Seitz, who was Eugene Wigner’s first graduate student, Bardeen became Wigner’s second graduate student. Seitz and Bardeen, along with Conyers Herring, Wigner’s third graduate student, and a small group of John Slater’s graduate students at MIT, comprised the first generation of American theoretical physicists who were trained to apply quantum mechanics to real solids. In 1933, focusing on sodium, Wigner and Seitz developed a seminal approximate method for calculating real band structures. To this evolving framework Bardeen contributed his thesis calculation of the work function of metals, a measure of the energy required to remove an electron from the surface of a metal. He used a wave function describing each electron with its own single-electron wave function and in approximating the distribution of electrons at the surface of the metal, included higher contributions arising from the forces which were correlating electrons with each other. In later life, Bardeen claimed that Wigner taught him how to attack problems by reducing them to their bare essentials.
In the spring of 1935, Bardeen was invited to become a Junior Fellow in Harvard’s Society of Fellows despite the uncomfortable tongue-tied interview he had with a group of Senior Fellows. During his three years of research at Harvard, Bardeen focused on “many-body” problems where the interactions between electrons, or between electrons and the lattice, play a significant role. He was often frustrated because physics was not yet equipped with adequate theoretical tools for treating such interactions; these tools would evolve after World War II. In Bardeen’s first year at Harvard, he became acquainted with William Shockley, then completing his doctoral thesis at MIT under Slater. During Bardeen’s second semester, Shockley accepted a position at Bell Telephone Laboratories, the research and development arm of the American Telephone and Telegraph Company. From that position, Shockley would later help bring Bardeen to Bell Laboratories. An important influence on Bardeen during his Harvard
period was the experimental physicist Percy Bridgman, widely recognized for his pioneering studies of the physics of materials under high pressure (and sometimes credited with developing the philosophy of operationalism, often associated with Einstein’s development of the special theory of relativity). Bardeen found applying quantum theory to Bridgman’s data so fulfilling that in later years he would try to recreate the model of working closely with an experimentalist whenever possible.
One of the problems Bardeen struggled with unsuccessfully at Harvard was explaining superconductivity, the complete loss of electrical resistance in certain metals and alloys when their temperature falls below a critical transition temperature. Numerous theories of superconductivity had been proposed in the 1920s and early 1930s following the development of quantum mechanics, but they all failed. In 1935, a breakthrough occurred when the brothers Fritz and Heinz London published a speculative empirical theory of superconductivity designed to explain the observed Meissner effect, the expulsion of magnetic field by superconductors. Bardeen was among those who immediately sensed the importance of the Londons’ suggestion of a “rigidity” of the ground-state wave function (rigid, because it is not much altered by a magnetic field) as a consequence of the proposed gap in energy between the ground state and the low-lying exited states. But he could not yet use this clue to develop a theory of superconductivity from first principles.
Bardeen married Jane Maxwell in June 1938, shortly after the Department of Physics of the University of Minnesota offered him his first teaching position. At Minnesota Bardeen continued to pursue superconductivity with a theory that assumed the only electrons that count are those near the edge of the Fermi surface. These, Bardeen believed, might create a field oriented opposite to the applied field, shielding the electrons inside from the applied field and causing the observed diamagnetism. In favorable circumstances, he argued, small displacements of the ions inside superconductors would cause the electrons to gain a small amount of energy that more than compensated for the energy spent on ionic displacement, causing gaps to form in the electronic structure. As the experimental numbers this theory predicted disagreed with the observed values by more than a factor of ten, Bardeen did not commit his calculation to print.
In Minnesota, the Bardeens’ first child, James Maxwell Bardeen, was born on 9 May 1939. By the time their second child, William Allan Bardeen, was born, on 15 September 1941, Bardeen had begun to move the family to Washington, DC, so that he could serve his country by researching the influence fields of ships at the Naval Ordnance Laboratory (NOL) to help allied troops defend against German magnetic firing mechanisms. The Bardeens’ third child, Elizabeth Ann Bardeen (called Betsy), was born on 25 April 1944, in the period when the family lived in Washington. All three children subsequently entered scientific careers: James and William studied physics and Betsy computing.
Bell Laboratories and the Transistor. Bardeen soon grew restless at NOL, unhappy both with his military engineering work, which diverted him from his physics research, and with the inflexible and chaotic military bureaucracy. He returned to fundamental physics as soon as the war ended, accepting an offer to work on basic solid-state physics in a new semiconductor group at Bell Laboratories headed by Shockley. The group Bardeen joined was a section of the laboratory’s recently established solid-state research department, modeled by the executive vice president Mervin Kelly on the successful multidisciplinary wartime laboratories. In the new semiconductor group, besides the two theorists Bardeen and Shockley, were two experimental physicists, Walter Brattain and Gerald Pearson, a chemist, Robert Gibney, and a circuit expert, Hilbert Moore. One goal was to replace vacuum tube systems, which had been the basis of the telephone system’s growth during the 1920s and 1930s, with semiconductor technology. Bardeen studied the wartime reports on silicon and germanium, which had been produced during the war because of the use of semiconductors in radar detectors.
Bardeen’s work leading to the transistor began soon after he arrived in October 1941, when Shockley asked him to examine a design that he had sketched about six months earlier for a silicon field-effect amplifier. The device did not work. Five months later, Bardeen had a theory to explain this failure. It assumed that a substantial number of electrons were trapped in surface states and thus could not contribute to conduction. Shockley’s interest in this research flagged over the course of the group’s two-year study of surface states.
The “magic month” culminating in the transistor began in November 1947 during the group’s study of surface states. On encountering a magnetic problem caused by droplets of water condensing on his apparatus, Brattain immersed the apparatus in various liquids and found that the photovoltaic effect he was studying increased whenever the liquid used was an electrolyte. After Bardeen suggested that ions in the electrolytes might be creating an electric field large enough to overcome the surface states, the team noticed that when water or an electrolyte was used they could vary the photo EMF (electromotive force) over a large range, indicating a possible way to build a field-effect semiconductor amplifier. Bardeen’s close interplay with Brattain, in which he served as “the brain” and Brattain as “the hands,” resembled his earlier collaboration with Bridgman (del Guercio et al., 1998).
Bardeen offered many suggestions for variations to try in the group’s evolving work aimed at inventing a semiconductor amplifier, for instance, to try different electrolytes and to use a slab of p-type silicon with an n-type “inversion layer,” in which the sign of charge carriers was opposite to that of carriers in the bulk material and where the carriers had higher mobility than in deposited thin films. One crucial suggestion was to replace the silicon altogether with a piece of the “high-back-voltage germanium” developed during World War II by the Purdue University group working under Karl Lark-Horowitz. Another was to substitute for the electrolyte an oxide film Brattain had seen growing on the germanium. With these changes, their experiment on 11 December 1947 showed amplification. But the current was flowing in the opposite direction than expected. Only gradually did Bardeen and Brattain realize that their oxide had washed off, allowing holes, empty electron states near the top of an otherwise filled energy band acting like positive particles, to flow into the germanium. Owing to this contact, the device they had built amplified on a different principle than by the field effect. To increase the signal, Bardeen now suggested their classic geometry, in which two narrowly separated metallic line contacts were pushed down on the germanium to allow the holes to flow closer to the input signal. This experiment worked the first time they tried it, on 16 December 1947. The device, later named the transistor, was born. Bardeen’s soft murmur to his wife Jane that evening, “We discovered something today,” was almost inaudible, but since he typically said nothing about his work she knew it had been a special day (Jane Bardeen, 1991c).
The invention of the transistor would in time change the world by making possible the microchip and all the devices that followed from it, but the discovery ruined the spirit of the Bell Laboratories semiconductor group. Shockley, who had been uninvolved in the invention of the original transistor, stunned Bardeen and Brattain when he tried to patent the invention in his name, hoping to base it on his suggestion of the field-effect amplifier. Shockley’s plan failed because the patent attorneys discovered that Julius E. Lilienfeld, a Polish-American inventor, had already patented the field-effect notion in 1930. Shockley further antagonized Brattain and Bardeen by preventing them from working on the consequences of their historic invention, a second transistor, known as the junction device, which could better be used commercially. The work at this stage was already tense, because Bardeen and Brattain, occupied with the tedious process of drafting patent applications, were anxious that physicists elsewhere, for instance, those working at Purdue, might scoop them. Indeed, in Paris, Heinrich Welker and Herbert Mataré would soon file a patent on a device similar to their invention. Meanwhile, Shockley continued to work secretly on his design for the junction device. But when John Shive demonstrated that holes could travel through the bulk of a semiconductor, Shockley suddenly announced his work, fearing that Bardeen would instantly apply the new clue and invent the junction transistor before he could take credit for it. Brattain and Bardeen were appalled when they learned that Shockley had hidden his work from the group (Riordan and Hoddeson, 1977, 163–186).
Bardeen considered taking a position at Oak Ridge National Laboratory directing the solid-state work of the reactor program. James Fisk, then at Harvard but scheduled to return to Bell Laboratories as the director of Physical Research, advised Bardeen to wait the crisis out. Bardeen returned to the work on superconductivity he had started at Minnesota. Unfortunately, while superconductivity was still the outstanding unsolved riddle of solid-state physics, in this period it was of little interest at Bell Laboratories. Bardeen worked on the problem alone. What soon riveted him to this work was a phone call he received on 15 May 1950 from Bernard Serin, an experimental physicist at Rutgers. In studying pure isotopes of mercury, Serin’s group found an isotope effect: the lighter the mass, the higher the temperature at which the material turns superconducting. Emanuel Maxwell at the National Bureau of Standards had found the same effect independently. Bardeen realized this meant “that electron-lattice interactions are important in determining superconductivity” (Handwritten notes, 15 May 1950. Bardeen papers, University of Illinois). In his Minnesota work, Bardeen had tried to explain the energy gap in the electronic structure of superconductors using a single-electron quantum mechanical model. He explored whether applying a small periodic distortion to the lattice could lower the energy and introduce band gaps near the Fermi surface. Although his initial attempt to use the new clue about the electron-lattice interactions failed to rescue his earlier theory, he felt quite sure he was on the right track and secured his priority in a letter to the Physical Review. He did so at roughly the same time that a colleague, Herbert Fröhlich, came to similar conclusions about the electron-lattice interactions. At this point, neither Bardeen nor Fröhlich could show how these interactions could actually lower the energy as was necessary to achieve superconductivity.
Bardeen continued to feel isolated in his work on superconductivity at Bell Laboratories. In October 1950, when he encountered Seitz at a physics conference, he asked whether Seitz knew of any jobs in academia. Seitz, who had recently moved to the University of Illinois, went directly to his dean and to the head of the Department of Physics who soon pieced together an offer for Bardeen jointly in physics and electrical engineering. Bardeen accepted in April 1951, and the family moved to Illinois during the summer of 1951.
University of Illinois and Theory of Superconductivity. Bardeen and his first graduate student, Nick Holonyak, became instant and unlikely friends. The bond that developed between the soft-spoken, mature, and meditative Bardeen and the talkative, young, and exuberant Holonyak resembled the relationship Bardeen had had with his extroverted Bell Labs partner Brattain, and earlier with his older brother William. Holonyak worked in the semiconductor laboratory, which was created in the fall of 1952 in the space that previously had housed the university’s historic ILLIAC computer. According to Holonyak, Bardeen never “picked up a pair of pliers,” but would come by the laboratory almost daily to encourage the students to learn for themselves how to conduct an experiment (Holonyak, 1991).
Although he was now back in academia, Bardeen maintained a number of industrial ties, the longest-lasting one with Xerox Corporation (initially called the Haloid Company), and others with General Electric and Super-tex, an electronics firm founded by Henry Pao, one of Bardeen’s students. Bardeen also participated in creating the Midwest Electronics Research Center, which helped industries develop their research capability in cooperation with research universities.
Once settled at Illinois, Bardeen immersed himself fully in the problem of superconductivity. Seeking new tools for dealing with the electron interactions in superconductors, he explored David Bohm’s recently developed theory of electron-electron interactions in plasmas.
Bardeen invited Bohm’s graduate student David Pines to work with him at Illinois as his postdoctoral assistant. Based on Pines’s study of the interactions in the simpler case of the polaron, Bardeen and Pines developed a formalism for treating the coupling of electrons to the lattice vibrations. They found that in cases where the energy transfer is small, the attractive interaction is stronger, suggesting a possible mechanism for superconductivity. In the meantime, Bardeen examined all the work that had been done on superconductivity, while preparing a long review article on the topic published in 1956 in the Handbuch der Physik.
In the fall of 1953, J. Robert Schrieffer, who had written an undergraduate thesis at MIT under Slater, joined the graduate physics program at Illinois. Schrieffer chose Bardeen as his thesis advisor and, by the spring of 1955, had selected the theory of superconductivity as his thesis topic. As Pines had accepted a teaching post at Princeton, Bardeen invited Leon Cooper, a young theorist with a field theory background, to join him as a postdoctoral associate. In the last months of 1955, Cooper showed that if the net force between two electrons just outside the Fermi surface is attractive they would form a bound state lying below the normal continuum of states and separated from the continuum by an energy gap. It appeared clear that if the entire ground state of a superconductor was composed of such pairs, the state would have properties that were qualitatively different from those of the normal state and would be separated from the excited states by an energy gap. The solution to the long-standing riddle looked near, but a major hurdle remained: how to cope theoretically with the large number of overlapping electron pairs in a superconductor.
In the middle of this work, Bardeen was surprised to learn that along with Brattain and Shockley he had won the 1956 Nobel Prize for the invention of the transistor. Encouraging Cooper and Schrieffer to keep working on superconductivity, Bardeen traveled to Stockholm to accept his prize. He was ambivalent about doing so, not only because he did not wish to leave his work on super-conductivity hanging at this point, but because he was not quite sure the transistor deserved a Nobel Prize. He also felt embarrassed to be awarded a Nobel Prize before his teachers Wigner and Van Vleck had received theirs.
The turn in the team’s work on superconductivity came in the last days of January 1957, soon after Bardeen returned from Stockholm. While riding on a subway in New Jersey, Schrieffer wrote down a promising expression for the superconducting ground state wave function. Recognizing the implications, Bardeen moved the team into an intense period of work in which the three feverishly computed all the relevant experimental quantities, including the energy gap and the second-order phase transition. The Bardeen-Cooper-Schrieffer theory (BCS), published in July 1957, proved to be the triumphant solution of the problem which for four and a half decades had stumped all the best theorists in the world.
After steering his team to the discovery of BCS, Bardeen fell into the role of the guru of the Illinois Physics Department; he spent most days answering questions posed by his colleagues and students. Because of his experience and detailed knowledge of physics, he could often point directly to the heart of a problem or even to its solution. But there were the times when Bardeen’s colleagues could not grasp the master’s meaning and simply accepted his judgment. The fact that they sometimes accepted his intuition blindly caused a few embarrassments. His initial resistance to Brian Josephson’s 1962 theory predicting that electron pairs in superconductors can tunnel quantum mechanically through a thin barrier separating two superconductors became the subject of a famous debate staged between Bardeen and Josephson at a major conference in 1962. Josephson won the debate.
In 1965, President Lyndon Johnson honored Bardeen with the National Medal of Science, the nation’s highest award for scientific achievement. Bardeen worried that the Swedish Academy of Sciences would hold to its tradition of never awarding a person a Nobel Prize twice in the same field, and thus rob Schrieffer and Cooper of their well-deserved honor. But in 1972, the Nobel Committee broke precedent and awarded Bardeen, Cooper, and Schrieffer the Nobel Prize for their theory of superconductivity. Less than two years later Bardeen retired from teaching at the age of 65. He nevertheless continued to work on research most days, with his office door open to colleagues and students. Among the few changes colleagues observed was that Bardeen stopped wearing a tie when he came to the university.
Throughout his time at Illinois, Bardeen occasionally served on national advisory panels, for example, in 1951 for the Office of Naval Research (ONR), and from 1959 through 1962 on the President’s Science Advisory Committee (PSAC) under Dwight D. Eisenhower and then John F. Kennedy. In 1968, he began a term as president of the American Physical Society (APS), which unfortunately included the violence that erupted during the 1968 Democratic National Convention in Chicago as a consequence of protest against the war in Vietnam. Bardeen found himself mediating a conflict between those who wished to cancel the Chicago APS meeting to protest the brutality of police actions and those who felt that canceling the meeting to make a political comment was an inappropriate use of the APS organization.
Bardeen initially resisted the invitation in 1981 to serve on President Ronald Reagan’s White House Science Council (WHSC), the replacement for PSAC, which President Richard Nixon had abolished in 1973. Bardeen reluctantly agreed to serve when his colleagues argued that a man of his knowledge and convictions was needed on the committee. Bardeen stepped down from the WHSC shortly after Reagan and his science advisor George Key-worth committed the United States, without consulting the WHSC, to the space-based missile defense program known as the Strategic Defense Initiative (SDI) (or popularly, as Star Wars). The SDI program so worried Bardeen that he wrote several articles about its dangers, including a New York Times editorial on the subject in May 1986, coauthored with Hans Bethe, although it was largely written by Kurt Gottfried.
Last Years. During the 1980s, Bardeen’s scientific work was largely focused on a novel quantum mechanical theory of charge density waves (CDWs), a phenomenon he believed could be explained in similar terms as superconductivity. The many-body physics community was initially intrigued by Bardeen’s theory of CDWs, but as time progressed, more and more physicists preferred the competing classical model, which predicted measurable relationships between the amount of impurities in the materials and the threshold voltage at which the CDWs begin to slide. As Bardeen’s theory lost ground, he felt increasingly bitter about the opposition; his own confidence in the theory persisted to the end of his life. Bardeen described the CDWs in 1989 as “a beautiful example of macroscopic quantum mechanics, with many analogies to superconductivity,” and he insisted that all the evidence “indicates that it is necessary to treat CDW metals as macroscopic quantum systems with quantum tunneling as an essential feature” (Bardeen, 1989).
Bardeen’s friendship with Holonyak offered a partial antidote for the unhappiness he experienced from the mid-1980s on. For a time he was able to relax and take Holonyak’s advice: “Look, if it’s a good day and you have such an inclination, go play golf” (Holonyak, 1998a). But by the end of the 1980s, Bardeen’s health was failing seriously. With his vision impaired by macular degeneration and with gout in his legs, golf became extremely difficult. Yet when the physics community was shaken by the excitement arising from the 1987 discovery of high temperature superconductivity, Bardeen, like many other theorists, jumped on the bandwagon and tried to develop a theory for this phenomenon.
In December 1990, the month in which Bardeen’s last article about the CDWs appeared in Physics Today, physicians in Urbana aspirated nearly a liter of fluid from his chest. X-rays revealed a mass in his lungs. A bronchoscopy and a mediastinoscopy at Boston’s Brigham and Women’s Hospital showed that his cancer had spread, thus surgery was out of the question. The surgeon, Dr. David Sugarbaker, marveled at Bardeen’s calm dignity in the face of his own mortality and suggested radiation, but on 30 January 1991, before any radiation could be administered, Bardeen died of a massive heart attack. Jane brought her husband’s ashes home to Champaign-Urbana. In May, the family buried them in Madison. On 31 March 1997, Jane also died, seven days short of her ninetieth birthday. Their son William designed a single low stone monument for the graves of both his parents, with a pattern referring to his mother’s interest in the natural world and his father’s two Nobel Prizes.
The largest collection of Bardeen’s personal and family papers is held by William and Marjorie Bardeen in Warrenville, Illinois. Many of Bardeen’s scientific papers can be found in the University of Illinois Archives in Urbana, Illinois. Bardeen’s Bell Laboratories notebooks belong to Lucent Technologies. The interviews with John Bardeen, David Bohm, J. Robert Schrieffer, and William Shockley, as well as the 1991 interviews with Frederick Seitz cited here, can be found at the Center for History of Physics of the American Physical Society. All other interviews cited here can be found at the University of Illinois.
WORKS BY BARDEEN
With Eugene Wigner. “Theory of the Work Function of Monovalent Metals.” Physical Review, series 2, 48 (1935): 84-87.
With Walter Brattain. “The Transistor: A Semi-Conductor Triode.” Letter. Physical Review, series 2, 74 (1948): 230–231.
With Walter Brattain. “Physical Principles Involved in Transistor Action.” Physical Review, series 2, 75 (1949): 1208–1225. “Theory of Superconductivity. Theoretical Part.” In Handbuch der Physik, vol. 15. Berlin: Springer, 1956.
With Leon N. Coooper and J. Robert Schrieffer. “Theory of Superconductivity.” Physical Review, series 2, 108 (1957): 1175–1204.
Interviews: By Lillian Hoddeson. 12 and 16 May 1977, 1 and 22 December 1977, and 13 February 1980. By Hoddeson and Gordon Baym. 14 April 1980a.
“Reminiscences of the Early Days in Solid State Physics.” Proceedings of the Royal Society of London A 371 (1980b): 77–83.
With Hans A. Bethe. “Back to Science Advisors.” New York Times, 17 May 1986.
“Classical versus Quantum Models of Charge-Density-Wave Depinning in Quasi-One-Dimensional Metals.” Physical Review B 39 (15 February 1989): 3528–3532.
“Superconductivity and Other Macroscopic Quantum Phenomena.” Physics Today43, no. 12 (1990): 25–31.
Bardeen, Jane. Interviews: By Lillian Hoddeson and Irving Elichirigoity. 6 June 1991a. By Vicki Daitch. 29 September 1991b. By Brian Pippard, David Pines, Lev Gor’kov, Ansel Anderson, Gordon Baym, Lillian Hoddeson, and Charles Slichter. 9 October 1991c. By Vicki Daitch. 23 November 1993. By Vicki Daitch. 2 December 1994.
del Guercio, G., et al. Transistorized! Documentatary film. KTCA-ScienCentral, PBS, 1998.
Hoddeson, Lillian. “The Discovery of the Point-Contact Transistor.” Historical Studies in the Physical Sciences 12, no.1 (1981a): 41–76.
———. “The Emergence of Basic Research in the Bell Telephone System, 1875–1915.” Technology and Culture 22 (1981b): 512–544.
Hoddeson, Lillian, Ernest Braun, Jurgen Teichmann, and Spencer Weart, eds.Out of the Crystal Maze: Chapters from the History of Solid-State Physics. New York: Oxford University Press, 1991.
Hoddeson, Lillian, and Vicki Daitch. True Genius: The Life and Science of John Bardeen. Washington, DC: Joseph Henry Press, 2002.
Holonyak, Nick. Interviews: By Lillian Hoddeson and Fernando Irving Elichirigoity. 29 May 1991. By Vicki Daitch, 21 January 1993. By Hoddeson and Riordan. 30 July 1993. By Hoddeson. 12 June 1998a. By Hoddeson and Daitch. 6 August 1998b. By Daitch. 6 December 2000.
Riordan, Michael, and Lillian Hoddeson. Crystal Fire: The Birth of the Information Age. New York: W. W. Norton, 1997.
Bardeen, John 1908–1991 Brattain, Walter H. 1902–1987 Shockley, William B. 1910–1989
Brattain, Walter H.
Shockley, William B.
Inventors of the Transistor
John Bardeen, Walter H. Brattain, and their boss William B. Shockley at AT&T's Bell Labs in Murray Hill, New Jersey, had a job to do. AT&T needed a way to amplify voices, which tended to get "lost" in static when traveling through more than 1,610 kilometers (1,000 miles) of telephone lines. These physicists were intent upon inventing a device to amplify sound in order to replace bulky, fragile, and expensive vacuum tubes . In December of 1947, after two years of hard work, they succeeded with a piece of V-wedged germanium and a strip of gold foil. Even though the newly termed semiconductor transistor was one fiftieth of the size of vacuum tubes and drew one millionth of the electricity, they had no idea their invention would change the face of the twentieth century. The three were awarded a Nobel Prize in Physics in 1956 for their discovery.
Nicknamed "Whispering John" because of his soft-spoken manner, Bardeen was born in Madison, Wisconsin, on May 23, 1908. He earned a bachelor's degree in electrical engineering in 1928, and his master's degree in 1929, both from the University of Wisconsin. He spent three years researching geophysics at the Gulf Research Laboratories in Pittsburgh, Pennsylvania. Leaving this position, he pursued studies in mathematical physics at Princeton University, receiving his Ph.D. in 1936.
Bardeen then became a junior fellow of the Society of Fellows at Harvard University. An assistant professorship at the University of Minnesota followed. After that, Bardeen worked at the Naval Ordinance Laboratories in Washington, D.C. In the fall of 1943, Bardeen left there to study solid state physics at Bell Labs. Soon after the transistor discovery, Bardeen and Brattain disputed the implication that their boss, Shockley, was also credited with the invention.
Bardeen left Bell Labs in 1951 to become a professor of electrical engineering of physics at the University of Illinois. Once in Illinois, and along with graduate students L.N. Cooper and J.R. Schrieffer, Bardeen discovered microscopic superconductivity during 1956 and 1957. He was awarded a second Nobel Prize in 1972, becoming the third Nobel laureate after Marie Curie and Linus Pauling to win the coveted prize a second time.
Experts in the field have compared Bardeen's gift of physics to Wolfgang Mozart's gift of music. Bardeen influenced almost every field of physics and continued publishing papers in his field until his death. He was bestowed with numerous awards and honors representing national and worldwide recognition for his efforts. Bardeen died on January 30, 1991, at age 82, of a heart attack, in Boston, Massachusetts.
Walter H. Brattain
Brattain was born in Amoy, China, on February 10, 1902. His family moved back to the United States soon after his birth. Brattain grew up on a ranch in Washington. He earned a bachelor's degree from Whitman College in 1924 and a master's degree from the University of Oregon. He earned his Ph.D. at the University of Minnesota. His first post-graduate job was at the National Bureau of Standards, but he soon left there to get back into physics. Bell Labs hired Brattain in 1929. He interrupted his stint at Bell Labs to work on ways to detect submarines during World War II, but returned after the war.
Brattain's partnership with Bardeen, whom Brattain met through his brother, was a great success. Brattain had an excellent reputation as an experimenter. Bardeen, the theoretical physicist, watched the experiments. He would then ask Brattain to modify them to test new theories. Together, the two developed the first transistor, while working under the supervision of Shockley. Because of friction, Brattain eventually transferred out of Shockley's department, but he continued to work at Bell Labs until his retirement in 1967.
Brattain also lectured at Harvard University, the University of Minnesota, and the University of Washington. He was also awarded several honorary degrees. He viewed his accomplishments with modesty, saying he was fortunate to be in the right place at the right time. He was a member of the National Inventors Hall of Fame. Brattain died of Alzheimer's disease in Seattle, Washington, on October 13, 1987, at the age of 85.
Born in London, England, on February 13, 1910, Shockley grew up in Palo Alto, California. He received his bachelor's degree from California Institute of Technology and his Ph.D. from Massachusetts Institute of Technology in 1936. Then he began working at Bell Labs in New Jersey. During World War II, he directed research on anti-submarine technology for the U.S. Navy, but like Brattain, returned to Bell Labs. In 1945 he was named the director of solid state physics for Bell Labs.
Although he was not present at the first successful transistor experimentation with Bardeen and Brattain, in the weeks following that discovery, Shockley contributed a series of insights that contributed to the understanding of semiconductor materials, and developed several theories about another type of amplification device, the junction transistor. He also formulated many of the theories that allowed silicon chips to be mass-produced.
In 1956 Shockley left Bell Labs to form his own company, Shockley Semiconductor Laboratories, with the intent of producing silicon transistors. He established his new company near Palo Alto, California. Eventually, Shockley's abrasive management style led to the departure of several of his employees, including Gordon Moore and Robert Noyce, who then went on to establish Fairchild Semiconductors and later, the Intel Corporation. Because so many of these companies were founded in that area, the region became known as Silicon Valley .
Later in life, Shockley accepted an appointment at Stanford University, where he formulated several theories about genetics. He withstood substantial criticism regarding his race-based theories, especially since the subject was deemed out of his area of expertise, physics. Bardeen died of prostate cancer on August 12, 1989, at the age of 79.
see also Bell Labs; Digital Logic Design; Integrated Circuits; Intel Corporation; Transistors; Vacuum Tubes.
Mary McIver Puthawala
Moore, Gordon E. "Solid State Physicist: William Shockley—He Fathered the Transistor and Brought the Silicon to Silicon Valley but Is Remembered by Many Only for his Noxious Racial Views." Time. March 23, 1999, p. 160.
United Press International. "John Bardeen, at Age 82, Was an Electronics Pioneer." The Record, Bergen Record Corp. January 31, 1991.
John Bardeen. University of Illinois, December 5, 1995. <http://www.physics.uiuc.edu/people/jbardeen.html>
Walter Brattain. ScienCentral, Inc. and the American Institute of Physics, 1999. <http://www.pbs.org/transistor/album1/brattain/brattain2.html>
John Bardeen (1908-1991) was the first person to win the Nobel Prize twice in the same discipline. The first award was made for his part in the discovery of the transistor, and the second for his part in developing the theory of superconductivity.
John Bardeen was born in Madison, Wisconsin, on May 23, 1908. He was the son of Althea Harmer and D. Charles R. Bardeen, who was professor of anatomy and dean of the medical school at the University of Wisconsin. John Bardeen graduated from Madison Central High School in 1923 and earned bachelor and masters degrees in electrical engineering from the University of Wisconsin in 1928 and 1929 respectively.
Early Work and Doctoral Studies
In 1929 and 1930 Bardeen worked as a research assistant in electrical engineering, investigating geophysical and other sorts of problems with professor Leo J. Peters. In 1930 Peters and Bardeen took positions with Gulf Research and Development Corporation in Pittsburgh, where they worked on some early applications of geophysics to petroleum prospecting.
Bardeen resigned from Gulf in 1933 to resume his formal studies. He earned his doctorate at Princeton University in 1936, with a mathematical thesis on the work function of metals. His advisor at Princeton was Eugene Wigner. Between 1935 and 1938 Bardeen was a member of the Society of Fellows at Harvard University, where he investigated further problems in the physics of metals with Percy Bridgman and J. H. Van Vleck. (It is worth noting that Van Vleck, who had first taught quantum mechanics to Bardeen in 1928 and 1929 at the University of Wisconsin, also gave Walter H. Brattain [one of the other inventors of the transistor] his first course in quantum mechanics when Brattain was a graduate student at the University of Minnesota.)
First Efforts at Theory of Superconductivity
From 1938 to 1941 Bardeen was an assistant professor of physics at the University of Minnesota. During this time he made his first efforts at devising a theory of superconductivity.
In a superconducting medium, electrical resistance drops to zero below the critical temperature, and currents once begun flow indefinitely. (The phenomenon was first observed in 1911 by Kammerligh Onnes for the element mercury, for which the critical temperature is 4.2 K.-Kelvin). In 1933 it was discovered that a fundamental property of superconductors is that they exclude magnetic fields from their interiors. Fritz and Heinz London were able to describe this property of superconductors in terms of macroscopic electrodynamic potentials, and in the same year Fritz London suggested that superconductivity was a quantum effect manifested on the macroscopic scale. It was more than 20 years, however, before a microscopic quantum theory of superconductivity was developed.
Bardeen's first attempt at a theory of superconductivity was based on the idea of a gap in the energy levels available to electrons. Electrons in superconducting states would be unable to absorb energy quanta unless the quanta were large enough to carry them over the energy gap into states representing normal conductivity, and they would consequently be trapped in superconducting states. Bardeen suggested that the energy gap would arise from interactions of the electrons in a conductor with static displacements of the crystal lattice, but his theory was unsuccessful.
In 1941 Bardeen left the University of Minnesota for a position with the Naval Ordnance Research Laboratory that lasted the duration of World War II. His concerns during the war were with underwater ordnance and minesweeping.
Nobel Prize in Physics
Bardeen was hired in the fall of 1945 by Bell Telephone Laboratories. Here he became a member of William Shockley's semiconductor research division, playing a major part in the invention of the point-contact transistor. It was Bardeen who determined why Shockley's first design for a semiconductor amplifier would not work; the energy states of a semiconductor favored the formation of a layer of charge on its surface, and this charge screened the interior from the influence of an electric field that was required by Shockley's design. Walter H. Brattain, another member of Shockley's group, investigated the properties of the surface states, and from his experiments grew a practical semiconductor amplifier, the transistor. The transistor was first demonstrated on December 16, 1947, and Bardeen, Brattain, and Shockley were awarded the Nobel Prize in Physics in 1956 for their discovery.
Bardeen's interest in superconductivity was reawakened in 1950 by the discovery of the isotope effect; it was found that the critical temperature for a superconductor depended on the square root of its atomic mass. Bardeen concluded that the interaction of electrons with ions in a crystal lattice must play an important part in superconductivity, but he was still unable to explain the phenomenon. The Ginzburg-Landau equations, which gave a phenomenological description of the ordering of conduction electrons in a superconductor but did not explain the causes of that ordering, also appeared in 1950.
More Research on Superconductivity
Bardeen left Bell Laboratories in the fall of 1951 for a professorship at the University of Illinois. In 1955 he renewed his research on the phenomenon of superconductivity, this time with the aid of his graduate student J. R. Schrieffer and of Leon N. Cooper. In 1956 Cooper discovered that an attractive potential between pairs of electrons could give rise to a gap in the energy levels available to electrons, and hence to a condensation of electrons in superconducting states. The attraction between electrons is not direct, in fact, but arises from a dynamic interaction of pairs of electrons with the crystal lattice. An electron may produce a vibration of an ion in the lattice, and this vibration will be experienced by a second electron as an attraction towards the first electron. Bardeen, Cooper, and Schrieffer discovered that the pairing of the electrons is such that (for a state in which no current flows in the superconductor) an electron with a given momentum and spin will be paired with an electron having the opposite momentum and spin. The two electrons are not close together, and in order for the pairing to occur all pairs of electrons must have the same net momentum. Hence the superconducting state is stable against perturbations since one Cooper pair cannot be destroyed without destroying all of them. As well as the vanishing resistance of a super-conductor, the theory of Bardeen, Cooper, and Schrieffer justified the equations of Ginzburg and Landau and London's description of the magnetic properties of a superconductor.
Although a magnetic field is excluded from the interior of a superconductor, it is possible for a magnetic field to destroy superconductivity; the cost in energy to exclude magnetic flux from the superconductor may be greater than the energy gained in the transition to the superconducting state, and the superconductor reverts to its normal condition. For type I superconductors, the fields necessary to destroy superconductivity are quite small. In some type II superconductors fairly strong magnetic fields can be tolerated, and alloys designed to have type II superconducting properties can be used to make practical superconducting electromagnets.
For their successful model of superconductivity, Bardeen, Cooper, and Schrieffer were awarded the Nobel Prize in physics in 1972. Subsequent refinements of their work have produced ever better agreement of theory and experiment.
Honors and Awards
Among many other honors, John Bardeen was elected to the National Academy of Sciences in 1954. He married Jane Maxwell in 1938, and they had three children. After 1975 he served as emeritus professor at the University of Illinois. He died in Boston on January 30, 1991, as the result of heart failure following surgery that had revealed the presence of lung cancer.
In 1994, The Minerals, Metals and Materials Society established the John Bardeen Award which recognizes individuals who have made outstanding contributions and shown leadership in the field of electronic materials.
Bardeen, Shockley, and Brattain recount their experiences in developing the transistor in their Nobel addresses: John Bardeen, "Semiconductor research leading to the point contact transistor, " Nobel Lectures: Physics, 1942-1962 (Amsterdam, 1964); William Shockley, "Transistor technology evokes new physics, " ibid. ; and Walter H. Brattain, "Surface properties of semiconductors, " ibid. (Appended to each of these addresses is a short biography of the author.) Developments in the understanding of superconductivity through 1972 are discussed in their Nobel addresses by Schrieffer, Cooper, and Bardeen: J. R. Schrieffer, "Macroscopic quantum phenomena from pairing in superconductors, " Science, 180 (1973); Leon N. Cooper, "Microscopic quantum interference in the theory of superconductivity, " Science, 181 (1973); and John Bardeen, "Electron-phonon interactions and superconductivity, " ibid. Bardeen can be found on the World Wide Web on the Minerals, Metals and Materials Society's page, <http://www.tms.org/Society/Honors/1997/Bardeen97.html>. and at <http://www.invent.org/book/booktext/5.html>. □
(b. 23 May 1908 in Madison, Wisconsin; d. 30 January 1991 in Boston, Massachusetts), theoretical physicist, educator, and two-time Nobel Prize winner who co-invented the transistor.
Bardeen was one of four children of Charles Russell Bardeen, a professor of anatomy and dean of the medical school at the University of Wisconsin, and Althea Harmer, an interior designer. His mother died in 1920 and his father married Ruth Hames later that year; the couple had a daughter, Bardeen’s half sister.
Bardeen attended elementary school in Madison, skipping three grades before entering University High School. He later transferred to Madison Central High School, from which he graduated in 1923. Bardeen enrolled at the University of Wisconsin, where in 1928 he earned a B.S. degree, and in 1929 an M.S. degree, both in electrical engineering. From 1930 to 1933 he worked as a geophysicist at the Gulf Research and Development Corporation in Pittsburgh.
In 1933 Bardeen began doctoral studies in mathematical physics at Princeton University. Working with the renowned Eugene Wigner, he focused on quantum theory as applied to solids and wrote his thesis on the attractive forces of electrons within metals. He received his Ph.D. from Princeton in 1936, a year after having accepted a postdoctoral research fellowship from Harvard University. There he worked with Professors John Van Vleck and Percy Bridgman on the problems in electrical conduction and cohesion in metals. The fellowship ended in 1938, and Bardeen taught physics as an assistant professor at the University of Minnesota from 1938 to 1941. During World War II, from 1941 to 1945, he served as a civilian physicist for the Naval Ordnance Laboratory in Washington, D.C.
In 1945 Bardeen took a job with Bell Telephone Laboratories in Murray Hill, New Jersey. Working with Walter H. Brattain and William Bradford Shockley in research on semiconductors, the three attempted to create a solid-state amplifier that would replace vacuum tubes in electronic devices. They concentrated on silicon and germanium, two of the better-understood semiconductors of that time. Shockley’s idea was to control electron flow within the semiconductor by applying an electric field from outside, expecting that the field would produce amplification. When Shockley’s experiments failed, Bardeen hypothesized that atoms on the surface of the semiconductor might be preventing electrical signals from getting to the interior and producing the desired effect. The group shifted its focus temporarily in order to study and better understand surface phenomena in semiconductors.
By December 1947 Bardeen and Brattain had made the first successful semiconductor amplifier. It consisted of a piece of germanium with two closely spaced pieces of gold on one side (point contacts) and a broad tungsten contact on the other side. When an electrical current was fed to one of the gold contacts, it appeared in greatly amplified form on the other side. The device had transferred current from a low-resistance input to a high-resistance output. The invention was named “transistor” because it exhibited the property of transfer resistance. The transistor could perform the functions of a vacuum tube in one-fiftieth of the space and with one-millionth of the power. It created virtually limitless possibilities in the field of electronics. The public used transistors in hearing aids in 1953 and in transistor radios in 1954. By the late 1950s the first transistorized computers were available. In 1956 Bardeen, Brattain, and Shockley shared the Nobel Prize in physics for their research on semiconductors and the discovery of the transistor effect.
Bardeen left Bell Labs in 1951 to become professor of physics and electrical engineering at the University of Illinois at Urbana-Champaign. There he began earnest research on the phenomenon of superconductivity, which had interested him since graduate school. In 1955 Bardeen teamed with Leon Cooper and John Robert Schrieffer to investigate how certain metals, at very low temperatures, suddenly lose all electrical resistance. By 1957 the trio had been successful in demonstrating their theory that electrons within the metals, when subjected to the necessary low temperatures, were aligned and moving in such a way as to create a coherent, rather than random, state, resulting in the superconductive effect. The theory, which became known as the BCS theory (for Bardeen Cooper Schrieffer), is widely considered to be one of the most important developments of modern theoretical physics. In 1972 the three men shared the Nobel Prize in physics for their jointly developed theory on superconductivity. Bardeen became only the third Nobel laureate to win the prize twice and the only person in history up until that point to have received two Nobel prizes in the same field.
Bardeen retired in 1975 but remained professor emeritus at the University of Illinois until his death. His professional memberships included the National Academy of Sciences, the American Academy of Arts and Sciences, the American Physical Society, of which he was president in 1968–1969, and the Royal Society of Great Britain. He was a member of the Center for Advanced Study at the University of Illinois from 1951 to 1975. Bardeen was on the President’s Science Advisory Committee from 1959 to 1962 and on the White House Science Council in the 1980s. He served as consultant to the Xerox Corporation in Rochester, New York, from 1952 to 1982 and was a member of its board of directors from 1961 to 1974. He was an associate editor of Physical Review from 1949 to 1952 and then again in 1956 for several years. Bardeen’s many awards and honors included the Stuart Ballantine Medal of the Franklin Institute (1952), the Oliver E. Buckley Solid State Physics Prize of the American Physical Society (1954), the John Scott Medal of the City of Philadelphia (1955), the Fritz London Award (1962), the National Medal of Science of the National Science Foundation (1965), the Presidential Medal of Freedom (1977), the Lomonosov Prize of the USSR Academy of Sciences (1988), and sixteen honorary degrees.
In July 1938 Bardeen married Jane Maxwell, a biologist and teacher. They had three children. Friends described Bardeen, an avid golfer, as a family man and as remarkably intelligent, soft-spoken, and modest. He died of a heart attack following surgery in Boston and is buried in Forest Hill Cemetery in Madison.
Bardeen once told a reporter, “I knew the transistor was important, but I never foresaw the revolution in electronics it would bring.” In 1990 Life magazine named Bardeen one of the 100 most influential Americans of the twentieth century. On Bardeen’s death, Dr. Robert M. Berdahl, then vice chancellor of the University of Illinois, said of him, “There are few people who had a greater impact on the whole of the twentieth century.”
A Collection of Professor John Bardeen’s Publications on Semiconductors and Superconductivity was published in 1989. The text of Bardeen’s 1956 Nobel lecture and a short biography appear in Nobel Lectures in Physics, 1942–1962 (1964). Bardeen is profiled twice in The Nobel Prize Winners: Physics (1989). A special issue of Physics Today (Apr. 1992) details Bardeen’s life and work. Obituaries are in the New York Times, Boston Globe, and Los Angeles Times (all 31 Jan. 1991). An oral history transcript, “Reminiscences of John Bardeen” (1963), is at the Oral History Collection at Columbia University.
In 1972 John Bardeen did something that no other physicist, not even Albert Einstein, had ever done. He won his second Nobel Prize in physics. The first was awarded to him (and to Walter H. Brattain and William Shockley) in 1956 for "investigations on semiconductors and the discovery of the transistor effect."
Their pioneering efforts ushered in the age of modern electronics and the integrated circuit, which eventually spawned the computer chip and the cell phone. Arguably, the transistor (and all of the devices it has made possible) is the single most important invention of this modern age and ranks with fire for its effects upon society and civilization.
Bardeen (along with Leon Neil Cooper and John Robert Schrieffer) won a second Nobel Prize in 1972 for "their jointly developed theory of super-conductivity," usually called (using the last initials of the three scientists) the BCS theory. In essence, BCS theory explains the phenomenon of superconductivity in Type I superconductors—metals , such as mercury, lead, and niobium.
According to BCS theory, at extremely low temperatures the lattice structures in these metals are very well-ordered and have little intrinsic vibrational motion. As an atom in a Type I superconductor gives up electrons to the Fermi conduction levels , it becomes a positively charged point in a sea of electrons. Below the critical temperature (the temperature at which a metal becomes superconducting), electrons in this Fermi level interact with the lattice atoms, producing vibrational motion that, in turn, interacts with a second electron. The result is the passage of electrons in the metal as "Cooper pairs," which move through the metal with zero resistance. Although Type I superconductors have not found extensive use because of their extremely low critical temperatures, the Type II or "alloy based" superconductors have radically changed science and technology, as they have enabled the construction of superconducting magnets, used in a range of devices, including magnetic resonance imaging (MRI) devices.
see also Einstein, Albert; Superconductors.
Todd W. Whitcombe
Brown, L. M.; Pais, A.; and Pippard, B., eds. (1995). Twentieth Century Physics. New York: American Institute of Physics Press.
Serafini, Anthony (1993). Legends in Their Own Time. New York: Plenum Press.
Flatow, Ira. Corporation for Public Broadcasting. "Transistorized!" Available from <http://www.pbs.org/transistorized>.
Godfrey, Stephen. Carleton University Department of Physics. "Superconductors: BCS Theory, Josephson Junctions, SQUIDS, etc." Available from <http://www.physics.carleton.ca/courses/>.
American physicist who was awarded the 1956 Nobel Prize for Physics, shared with Walter Brattain and William Shockley, for research on semiconductors and discovery of the transistor effect, which revolutionized the electronics industry. In 1972 Bardeen won a second Nobel Prize with Leon Cooper and J. Robert Schrieffer for their explanation of superconductivity, known as the BSC theory. Bardeen is one of only three people to have received two Nobel Prizes, and the only two-time recipient of the Nobel Prize for Physics.