Overhauser, Albert Warner (1925-) | Purdue University Libraries, Archives and Special Collections
On December 19, 1994, Professor Albert Overhauser was invited to a reception at the White House, where President Bill Clinton personally congratulated him on being awarded the National Medal of Science, the highest honor the United States bestows on its citizens for scientific achievement. Dr. Overhauser received the medal for his contributions to understanding the physics of solids, to theoretical physics and for the impact of his technological advances.
Overhauser was born August 17, 1925 in San Diego, California to Clarence Albert Overhauser and Gertrude Irene Pehrson. The family, including his sister Evaclaire Overhauser (Gatto), moved to San Francisco in 1935 where Al attended high school. His high school physics teacher, Ralph Britton, convinced him to give up his aspirations to become a civil engineer and instead to study physics. Following high school graduation, Al attended the University of California, Berkeley (1942-44) and then did a brief stint in the U.S. Naval Reserve (1944-46) during World War II. There he trained in electronics as a radar repair specialist, an experience he always felt was very valuable to him as a scientist. In 1946 he resumed his education at the University of California, Berkeley where in 1948 he received the BA, Magna Cum Laude in Physics and in Mathematics. He stayed on at Berkeley and in 1951 was awarded the Ph.D. in Physics for research carried out under the supervision of Charles Kittel.
He began his professional career at the University of Illinois during 1951-53. It was during this period that he developed his famous theory of dynamic nuclear polarization which shortly after its experimental confirmation became known by its current name, the Overhauser effect. In 1953 he joined Cornell University as an Assistant Professor, and was promoted to Associate Professor three years later. He left Cornell in 1958 to accept a position on the Scientific Research Staff of the Ford Motor Company in Dearborn, Michigan and was rapidly promoted there to Manager, Mathematical and Theoretical Sciences, in 1962, to Assistant Director, Physical Science Laboratory in 1969, and ultimately as Director of the Physical Sciences Laboratory in 1972. He left Ford in 1973 to become Professor of Physics at Purdue University. The following year he was named the Stuart Distinguished Professor of Physics at Purdue.
Overhauser married Margaret Mary Casey on August 25, 1951. They had eight children: Teresa, Catherine, Joan, Paul, John, David, Susan and Steven.
During his long career, Overhauser presented frequently and was invited to lecture at many of the most prestigious universities and research institutes around the world. He also delivered approximately 150 short talks for the American Physical Society. In addition to receiving the National Medal of Science, he has received numerous other distinguished honors. He was awarded the Honorary Doctor of Laws degree from Simon Fraser University (Canada) in 1998, and the Honorary Doctor of Science from the University of Chicago in 1979. He received the Alexander von Humboldt Senior Scientist Award in 1979-80. He became the Stuart Distinguished Professor of Physics at Purdue in 1974 and was awarded the Herbert N. McCoy Research Award at Purdue in 1978. In April 1975 he received the very prestigious Oliver E. Buckley Solid State Physics Prize awarded by the American Physical Society for his contributions to the advancement of knowledge in Solid State Physics.
He was a Fellow of the American Academy of Arts and Sciences, and a Visiting Scientist of the Japan Society for the Promotion of Science in 1978. In addition he served on numerous panels and boards including the Buckley Prize Committee (chair 1989, 1990); Board of Trustees, Argonne Universities Association; NSF Solid State Review Panel for Harvard, Cornell, Northwestern, Brown and the National Magnet Laboratory; and has served as Counselor-at-Large of the American Physical Society, 1982-86.
In October 1995, the Albert W. Overhauser Symposium took place on the campus of Purdue University. On this occasion relatives, friends, former students, post-docs and scholars came together to pay tribute to him on the occasion of his seventieth birthday. Among the professional colleagues in attendance and presenting papers were: Anthony Arrot, Morrel Cohen, Gene Dresselhaus, Mildred Dresselhaus, Helmut Fritsche, John Quinn, Frederick Seitz, Charles Slichter, Valentino Telegdi and Samuel Werner.
Perhaps Dr. Overhauser's most important contribution to science was his concept of dynamic nuclear polarization, which opened up new areas of science for research. The consequences of his discovery---known as the Overhauser Effect---for nuclear magnetic resonance, and through nuclear magnetic resonance for chemistry, biology and high-energy physics have been significant. The idea was originally so unexpected that it was resisted vehemently by the authorities in the field. Not until its existence was demonstrated experimentally by Slichter and Carver(1)in 1953 was it fully accepted.
In simplest terms, Overhauser was the first to demonstrate that it is possible to line-up, or to polarize, nuclear spins by a factor 1000 or so larger than one would expect based on then common intuitive notions. The trick that he used was first to impose microwave power on the nuclear-electron system and thereby excite the electronic spins to higher, non-thermal equilibrium states. Then because of the coupling between the electron and the nuclear spins, as the excited electron spins try to equilibrate to their lower states they reorient the nuclear spins. The nuclear spins then exhibit an enhanced polarization by a factor equal to the ratio of the electronic to the nuclear magnetic moments i.e., by about a factor of ≅ 1000.
When first proposed as a contributed paper at an APS meeting in April 1953, the proposal was met with much skepticism by a formidable array of physics talent. Included among these were notables such as: Felix Bloch (recipient of 1952 Physics Nobel Prize), Edward M. Purcell (recipient of Nobel Prize 1952 with Bloch and session chair), Isidor I. Rabi (recipient of Physics Nobel Prize, 1944) and Norman F. Ramsey (recipient of Physics Nobel Prize, 1989). Experimental confirmation of the Overhauser Effect was soon available via the experiments of Carver and Slichter(1), further convincing the research community of its validity.
Since the original discovery and its subsequent confirmation in a wide variety of experiments, the Overhauser effect has been used in Nuclear Magnetic Resonance applications to determine the structure of proteins and other molecules. This pervasive use of the Overhauser effect has spawned a variety of new terms. For example, the "Nuclear Overhauser Effect" (NOE) describes a collection of adaptations of the Overhauser Effect.
Besides its direct usage in scientific research, the Overhauser Effect is also the essential ingredient of an instrument which measures magnetic field strength to very high accuracy. Generically, such devices are known as Overhauser magnetometers. By using dynamic nuclear polarization, signal strength can be increased to such an extent that very accurate values for the magnetic field strength can be achieved.
Although perhaps not as widely known as his discovery of dynamic nuclear polarization Overhauser has a number of other scientific achievements to his credit. These are dispersed among his approximately 180 scientific publications. Overhauser was awarded the degree of Honorary Doctor of Laws at Simon Fraser University in 1998, not only for his work on dynamic nuclear polarization but also for the remarkable insight he offered into the nature of the physical world. In 1960 he predicted the existence of spin and charge density waves. This far-reaching concept led to a deeper understanding of the way electrons behave in metals. And while at Purdue University, Albert Overhauser, together with colleague Roberto Colella, constructed a neutron interoferometer, which he then used to show for the first time that gravity plays a role in quantum mechanics.