Lokvani Talks To Paul Tedrow
Paul and Prabha Tedrow, both scientists are long time residents of Lexington. Paul is one of the three MIT recipients of who has been awarded the 2009 Oliver E. Buckley Condensed Matter Prize from the American Physical Society. He received his S.B. degree from the Massachusetts Institute of Technology in June, 1961. He was introduced to low temperature research by carrying out a senior thesis under the direction of Dr. Emanuel Maxwell.
Dr. Tedrow attended graduate school in the Physics Department of Cornell University. He worked in the Low Temperature Laboratory of Professor David M. Lee throughout his time at Cornell. He received the Ph.D. degree in June, 1966. His research involved a study of the phase diagram of mixtures of the isotopes of helium, He3 and He4, at temperatures below 1K and at pressures near the solid-liquid phase boundary. He also learned about experimental superconducting tunneling by observing and assisting in the research of another graduate student, Prabha R. Kumbhare, who was measuring the energy gap of superconducting cadmium by tunneling. Dr. Tedrow and Dr. Kumbhare have been married since 1970.. He spent the summer of 1983 as a visiting scientist at Stanford University. He retired from MIT and physics in July, 1998.
Paul shared with us this outstanding achievement, and what it means to the scientific world and his own personal contribution.
Could you describe to us the pioneering work at MIT with the team that brought this honor.
I made the initial discovery thirty-nine years ago in collaboration with Dr. Robert Meservey, also of MIT. We were studying the behavior of electrons in superconductors exposed to intense magnetic fields. Superconductors are materials, most commonly metals, that have zero electrical resistance when cooled below a characteristic very low temperature. The most prominent and familiar property of electrons is their electrical charge, which produces the ordinary current and voltage phenomena we encounter every day. Because of quantum effects, however, electrons also have another important property known as spin, which causes them to behave like tiny magnets. Our research demonstrated for the first time that the electron spin could carry information in an electrical current and that that information could be detected by suitably designed superconducting or magnetic devices called tunnel junctions. The resulting devices were initially used for basic scientific probing of the superconducting and ferromagnetic states of metals. It was quickly realized that this phenomenon could be applied to new designs of electronic circuits, such as magnetic memories, but producing a successful and reproducible device proved difficult.
In 1981, Dr. Jagadeesh Moodera joined our group with the mission, among other things, of producing such a device. In the mid-eighties, however, the high-temperature superconductivity mania struck the world solid-state research community, causing research plans to be diverted for several years. In 1995, Dr. Moodera succeeded in producing the desired tunnel junction device, attracting considerable notice from commercial electronic interests and solid-state researchers. Recently, electronic circuits based on the phenomenon first observed in 1970 have appeared on the market. The field is sometimes called “Spintronics.” Dr. Meservey, Dr. Moodera and I have been chosen to receive the Oliver E Buckley Prize as a result of this work.
How can this discovery help in the future for various applications ?
The work is now being applied to commercially available electronic circuitry. As more information on materials properties, especially in the area of magnetic semiconductors, accumulates, more applications are likely to appear. A long-range use may be in the futuristic area of quantum computing, where spin effects are likely to be important to the implementation of such a technique.
What does this award mean to you ?
The Buckley Prize is the most prestigious award given by the American Physical Society for work in the area of Physics in which I spent my entire career, so it is both gratifying and exciting to have one’s efforts recognized in this way. The award has been given each year for about fifty years, and the list of previous recipients is very impressive, to say the least. We are joining an extremely select group of scientists.Bob Meservey and I realized in 1970 when we saw our first data that we had observed something that no one else had ever seen and that it was fundamental physics. Having the recognition implied by this award added to the satisfaction of that moment is the crowning event of our careers.
Is this research still ongoing ?
Dr. Meservey and I have retired, but Dr. Moodera is still carrying on a very active and successful program at MIT. Our work has produced a new mini-field of research that is being pursued also at many academic and commercial laboratories around the world.
Finally please describe some of the other community activities you are involved in ?
I had first learned about electron tunneling in graduate school at Cornell, where a fellow student, Prabha Kumbhare, was working in the same laboratory as I was and was doing a difficult tunneling experiment. In addition to providing me with valuable knowledge about electron tunneling, I got my first exposure to Indian culture. A number of years later, Dr. Kumbhare and I decided to get married. As a result, I have had a long and close interaction with the Indian community around Boston. One of the first couples we became acquainted with when we moved to Lexington, MA was Puran and Kamlesh Dang. This acquaintance eventually led to my being recruited to serve as Secretary of the Board of Directors of MITHAS, an MIT organization started by Puran Dang to sponsor Indian classical music and dance programs. Recently, I began a similar position with the steering committee of the organization Indian Americans in Lexington.
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