BCS theory, proposed by John Bardeen, Leon Neil Cooper, and John Robert Schrieffer ( BCS ) in 1957, is the first microscopic theory of superconductivity since its discovery in 1911.

In 1957 Bardeen and Cooper assembled these ingredients and constructed such a theory, the BCS theory, with Robert Schrieffer.

The 1950 Landau-Ginzburg theory of superconductivity is not cited in either of the BCS papers.

It is believed that BCS theory alone cannot explain this phenomenon and that other effects are at play.

The BCS theory, however, requires only that the potential be attractive, regardless of its origin.

BCS theory starts from the assumption that there is some attraction between electrons, which can overcome the Coulomb repulsion.

However, the results of BCS theory do not depend on the origin of the attractive interaction.

Extensions of BCS theory exist to describe these other cases, although they are insufficient to completely describe the observed features of high-temperature superconductivity.

The BCS theory gives an expression that shows how the gap grows with the strength of the attractive interaction and the ( normal phase ) single particle density of states at the Fermi energy.

* BCS theory predicts the dependence of the value of the energy gap E at temperature T on the critical temperature T < sub > c </ sub >.

* BCS theory correctly predicts the Meissner effect, i. e. the expulsion of a magnetic field from the superconductor and the variation of the penetration depth ( the extent of the screening currents flowing below the metal's surface ) with temperature.

BCS theory relates the value of the critical field at zero temperature to the value of the transition temperature and the density of states at the Fermi energy.

* The BCS theory reproduces the isotope effect, which is the experimental observation that for a given superconducting material, the critical temperature is inversely proportional to the mass of the isotope used in the material.

This is incorporated into the BCS theory, where lattice vibrations yield the binding energy of electrons in a Cooper pair.

* Dance Analogy of BCS theory as explained by Bob Schrieffer ( audio recording )

Eventually in 1965, John Bardeen, Leon Cooper and John Schrieffer developed the so-called BCS theory of superconductivity, based on the discovery that arbitrarily small attraction between two electrons can give rise to a bound state called a Cooper pair.

In 1957, John Bardeen, in collaboration with Leon Cooper and his doctoral student John Robert Schrieffer, proposed the standard theory of superconductivity known as the BCS theory ( named for their initials ).

BCS theory explains conventional superconductivity, the ability of certain metals at low temperatures to conduct electricity without electrical resistance.

BCS theory views superconductivity as a macroscopic quantum mechanical effect.

File: Bardeen. jpg | John Bardeen ( 1908 – 1991 ): awarded Nobel Prize in Physics in 1956 with William Shockley and Walter Brattain for the invention of the transistor and again in 1972 with Leon Cooper and John Robert Schrieffer for a fundamental theory of conventional superconductivity known as the BCS theory.

The BCS theory was set on a firmer footing in 1958, when Bogolyubov showed that the BCS wavefunction, which had originally been derived from a variational argument, could be obtained using a canonical transformation of the electronic Hamiltonian.

The package also included the BCS Championship Game, except in 2010 when the game was played at the Rose Bowl.

This was done successfully by the BCS theory in 1957, from which the penetration depth and the Meissner effect result.

In that time, the Big East has seen the emergence of new national players West Virginia rising to as high as No. 1 and was ranked in the Top 10 for three-straight years ( 2005, 2006, 2007 ) ( South Florida rising as high as No. 2, Cincinnati and Louisville both as high as No. 3, Rutgers as high as No. 7, Pittsburgh as high as No. 9, and Connecticut as high as No. 13 in BCS standings ).

The SEC was also the first NCAA Division I conference to hold a championship game ( and award a subsequent title ) for college football, and was one of the founding members of the Bowl Championship Series ( BCS ).

The 2011 BCS National Championship Game was held in Glendale on January 10, 2011.

It was the longtime host of the Fiesta Bowl, although the BCS game moved to University of Phoenix Stadium, located in Glendale, in 2007.

The first College Bowl game to feature two Australians was the 2012 BCS National Championship Game with punter Brad Wing from LSU and defensive end Jesse Williams for Alabama.

In 1998, the Fiesta Bowl became part of the Bowl Championship Series ( BCS ), and before 2007 every four years ( most recently in 2003 ) was the designee for the national championship game.

The Fiesta Bowl was the first BCS bowl to have had an entry from outside the parameters of the BCS ( the Big 12, Big Ten, Atlantic Coast Conference ( ACC ), Southeastern Conference ( SEC ), Pac-10, Big East, and Notre Dame have tie-ins, while all of the other conferences do not ).

It was the first time a BCS bowl matched-up two non-automatic qualifying teams ( i. e. two teams from conferences without automatic BCS bids ) and the first time that two teams who went undefeated faced each other in a BCS game outside of the National Championship.

The 2nd BCS World Championships was held in Miami, Florida, USA in July 2009, in conjunction with the World Corcom Championships

" The 2010 / 11 BCS showed overall violence was down 47 per cent on the level seen at its peak in 1995 ; representing nearly two million fewer violent offences per year.

In 2002 and 2006 ( when the Rose Bowl Game was the BCS National Championship Game ), the " Granddaddy of ' em all " was not held the same day as the parade ; the 2006 game was played on January 4.

In 2002 and 2006 ( 2001 and 2005 football seasons ), the Rose Bowl game was also the BCS National Championship Game.

The 2006 Rose Bowl game, which was also the BCS championship game, had a crowd of 93, 986 ; and a crowd of 94, 118 saw the 2011 Rose Bowl game between TCU and Wisconsin.

While the Big Ten supplied the " East " representative and the PCC, AAWU, or Pac-8 / 10 supplied the " West " representative from the 1947 Rose Bowl to the BCS era, statements about an " exclusive " Rose Bowl agreement existing during this period are not entirely accurate: the Big Ten was not part of any agreement for the 1961 and 1962 games and the status of the agreement for 1960 is questionable, at best.

However, this section covers the status of Rose Bowl agreements from the collapse of the PCC until the BCS era and the AAWU was not known by its current name during this period.

John Robert Schrieffer ( born May 31, 1931 ) is an American physicist and, with John Bardeen and Leon N Cooper, recipient of the 1972 Nobel Prize for Physics for developing the BCS theory, the first successful microscopic theory of superconductivity.

This is the BCS transition, discovered in 1957 by John Bardeen, Leon Cooper and Robert Schrieffer for describing superconductivity.

The original results of BCS ( discussed below ) described an s-wave superconducting state, which is the rule among low-temperature superconductors but is not realized in many unconventional superconductors such as the d-wave high-temperature superconductors.

Conventional superconductors are materials that display superconductivity as described by BCS theory or its extensions.

Unconventional superconductors are materials that display superconductivity which does not conform to either the conventional BCS theory or the Nikolay Bogolyubov's theory or its extensions.

These include some that do not superconduct at high temperatures, such as the strontium ruthenate oxide compounds, but that, like the high-temperature superconductors, are unconventional in other ways ( for example, the origin of the attractive force leading to the formation of Cooper pairs may be different from the one postulated in BCS theory ).

In 2008 a new class ( layered oxypnictide superconductors ), for example LaOFeAs, were discovered that do not include copper .< ref > An oxypnictide of samarium seems to have a T < sub > c </ sub > of about 43 K which is higher than predicted by BCS theory.

Cuprate superconductors ( and other unconventional superconductors ) differ in many important ways from conventional superconductors, such as elemental mercury or lead, which are adequately explained by the BCS theory.

A paper written with C. N. Yang showed that flux quantization in superconductors is direct evidence for the BCS theory of superconductivity based on Cooper pairing of electrons.