Cooper, Leon

Cooper, Leon Neil (1930- ) received the Nobel Prize in physics with Bardeen and Schrieffer for the BCS theory. Cooper pairs are named after him. 

Leon Billings. Sept. 8, 1997. Source for Muskie s reaction to Patterson testimony and their continued cooperation. 

Bardeen, Leon Cooper and John Robert Schrieffer, which, from their initials, was called BCS theory. 

Superconductivity has not only been beneficial to science and technology but also has been highly rewarding to its scientists. Thus far, Nobel Prizes in Physics have been awarded on four occasions to scientists working in this area. The first of these was for the discovery of superconductivity by Kamerlingh Onnes, awarded in 1913. In 1972 the prize went to John Bardeen, Leon Cooper, and Robert Schrieffer for the BCS theory. The following year (1973), the Prize was awarded to Brian Josephson, L. Esaki and I. Giaever for the... 

Kamerlingh Onnes, at the University of Leiden, discovered superconductivity in 1911. He found that the resistance of some metallic wires became zero at very low temperature it did not just approach zero, there was no dissipation of heat. At that time his laboratory was the only one equipped for studies at the temperature of liquid He (bp 4.1 K). Theoretical explanations of the phenomenon did not appear until the work of John Bardeen, Leon Cooper, and Robert Schrieffer in 1957. They received the Nobel Prize in Physics in 1972. The expense and difficulty of applying superconductivity to practical problems limits the applications. Nevertheless, superconductor magnets of very high field are now widely used in NMR in chemistry and the medical diagnostic applications of NMR called MRI (magnetic resonance imaging—they wanted to avoid the word "nuclear ). 

The author thanks the SMI-group members for their contributions but like to mention specially the cooperation in this field with Leon Abelmann, N. Kikuchi, Nguyen Dao, Martin Siekman and Rogelio Murillo. The Dutch Technology Foundation (STW) supports this work financially. 

The authors acknowledge the technical assistance of Carmela San-tomieri, Drusilla Wemett, Sarah Hallagan, Marcelle Hamshire, Elvira Di Ferrante, and Gilda Wolk. They are greatly indebted to Leon Schwartz and Gerald Cooper for their preparation of the illustrations. 

The modern theory of superconductivity was advanced in 1957 by three American physicists—John Bardeen, who had won the Nobel Prize the year before for inventing the transistor Leon N. Cooper, an expert in quantum theory (a theory developed in the 1920s to account for certain phenomena that could not be explained by classical physics) and John R. Schrieffer, who had specialized in electrical engineering before he switched to physics. 

The first forward step was taken by Leon Cooper, the slightly built graduate of the Bronx High School of Science in New York, a newly minted Ph.D. from Columbia, and the man Bardeen called the quantum mechanic from the East. Cooper had joined with Bardeen and Schrieffer at the University of Illinois to tackle the mystery of superconductivity. (Schrieffer, from the Massachusetts Institute of... 

BCS theory The modern theory of superconductivity. Named after John Bardeen, Leon Cooper, and John R. Schrieffer. 

Bardeen (along with Leon Neil Cooper and John Robert Schrieffer) won a second Nobel Prize in 1972 for their jointly developed theory of superconductivity, 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. 

The theoretical interpretation of the high temperature superconductors is still under development. The copper oxide ceramic superconductors obtain their paired conducting electrons from copper in mixed oxidation states of I and II or II and III, depending on the particular system. The paired conducting electrons are called Cooper pairs, after Leon N. Cooper. Cooper s name also gives us the C of BCS the BCS theory is an interpretation of superconductivity for low temperature superconductors (having Tc s of less than 40 K). 

John Bardeen, Leon N. Cooper, Robert Schrieffer 1917 Charles Glover BarkJa... 

Bardeen, John, Robert J Schrieffer and Leon N Cooper (1972)/or their jointly developed theory of superconductivity, usually called the BCES - theory Bednorz, J George, K Alexander Muller (1987)/or their important breakthrough in the discovery of superconductivity in ceramic materials, Lee, David M, Douglas D Osheroff and Robert C Richardson (1996)/br their discovery of superfluididity in helium-3 1 Samuel 5 6-12 and Sassoon Dale, p228 Josephus, Antiquities 6 1.1 1 Samuel 4 3ff... 

In 1911, Kamerlingh Onnes cooled a thread of pure mercury (1/20 mm or 0.002 inch diameter) in a capillary tube and found a smooth decrease in resistance as the temperature was lowered. At 4.2 K, he observed an abrupt decrease in resistivity from about 1/500 that at 273 K to 1/10 that at 273 K it reduced to about 1/10 at 1.5 K. Resistance had virtually disappeared and solid mercury became a superconductor at these incredibly low temperatures. Similar superconductivity transitions were observed by Kamerlingh Onnes for tin (3.8 K) and lead (6 K). The thermal motions of the atoms, associated with defects in conducting electricity, drastically decrease below the superconducting temperature (X). Heike Kamerlingh Onnes won the 1913 Nobel Prize in ph) ics. The modern theory of superconductivity was developed in 1957 by three physicists at the University of Illinois, John Bardeen (1908-91), Leon N. Cooper (1930- ), and John Robert Schrieffer (1931- ). They shared the 1972 Nobel Prize in physics (Bardeen also shared the 1956 Nobel Prize in physics for invention of the transistor he is the only double Nobel laureate in physics). 

The nature and origin of superconductivity was described in 1957 by John Bardeen, Leon Neil Cooper, and John Robert Schrieffer. Together they created the Bardeen Cooper Schrieffer (BCS) model. It occurs for many metals, alloys, intermetallic compounds, and doped semiconductors. The transition temperatures range from 92.5 K for Ybc CUjOg j, down to 0.001 K for the element Rh. And there are some materials that become superconducting only under high-pressure conditions. These materials all have to be extremely pure, even just one impurity in 10,000 atoms can severely affect the superconducting property. 

The situation is different in a superconductor. In a conventional superconductor, the electric current cannot be resolved into individual electrons. Instead, it consists of bound pairs of electrons known as Cooper pairs. The Cooper pairs are named for physicist Leon N. Cooper who, with John Bardeen and John Robert Schrieffer, formulated the first successful model explaining superconductivity in conventional superconductors. A key conceptual element in this theory is the pairing of electrons close to the Fermi level into pairs through interaction with the crystal lattice. 

Bardeen, Brattain, and Shockley shared the Nobel Prize In physics in 1956 for the discovery of the transistor. The importance of the transistor was recognized as soon as it was discovered. Although it was first demonstrated at the Bell Laboratories in December 1947, it wasn t announced until July 1,1948, after patent applications had been filed. John Bardeen was awarded a second Nobel Prize in physics in 1972, along with J. R. Schrieffer and Leon N. Cooper, for work on the theory of superconductivity. 

K. L. Ngai and C. Leon [2002] Cage Decay, Near Constant Loss, and Crossover to Cooperative Ion Motion in Ionic Conductors Insight from Experimental Data, Phys. Rev. B 66, 064308. 

The BCS theory, however, developed in 1957 by three physicists, John Bardeen, Leon Cooper, and Robert Schrieffer, does estabhsh a model for the mechanism behind superconductivity. Bardeen, Cooper, and Schrieffer received the Nobel Prize in physics in 1972 for their theory. It was known that the flux quantum was inversely proportional to twice the charge of an electron, and it had also been observed that different isotopes of the same superconducting element had different critical temperatures. Actually, the heavier the isotope, the lower the critical temperature is. The critical temperature, in K, of an isotope with an atomic mass, M, expressed in kg.moT can be predicted by the following equation ... 

---