Josephson, Brian David (1940-…), a British physicist, did important research on electromagnetic phenomena in materials at low temperatures. At the age of 22, he revealed significant discoveries on superconductivity, the disappearance of electrical resistance in some substances when very cold. For his work, Josephson shared the 1973 Nobel Prize for physics with Ivar Giaever of the United States and Leo Esaki of Japan.
When Josephson did his work in the early 1960’s, superconductivity was known in only a few materials, which had to be cooled to within a few degrees of absolute zero (-459.67 °F, or -273.15 °C, the lowest possible temperature). Josephson showed that several strange things would happen if two superconductors were separated by a thin layer of resistive material. An electric current could flow across this sandwich of materials, called a Josephson junction without an external voltage being applied. If a magnetic field is applied this “supercurrent” changes in complex ways. At a certain value of the applied field, the supercurrent falls to zero. But an ordinary current can still flow if a voltage is applied. In addition, if steady voltage is applied across the junction, an alternating current–that is, a reversing, back and forth current–flows across the junction, with a frequency depending on the strength of the voltage. These effects are called Josephson effects.
Josephson was born in Cardiff, Wales, and was educated at Trinity College, Cambridge England. Several of his scientific papers were published while he was still an undergraduate. He graduated in 1960 and was elected a fellow of Trinity College in 1962, while still working toward his Ph.D., which he gained in 1964.
Josephson was appointed a professor of physics at Cambridge in 1974 and a fellow of the Royal Society, one of the world’s foremost scientific organizations, in 1970. Beginning in the late 1960’s, Josephson’s research interests turned toward the scientific study of the mind and the nature of intelligence and consciousness.
