Restoration of particle number as a good quantum number in BCS theory

✍ Scribed by D.J. Rowe

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 168 KB
• Volume: 691
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(01)00588-7

✦ Synopsis

As shown in previous work, number projection can be carried out analytically for states defined in a quasi-particle scheme when the states are expressed in a coherent state representation. The wave functions of number-projected states are well-known in the theory of orthogonal polynomials as Schur functions. Moreover, the functions needed in pairing theory are a particularly simple class of Schur functions that are easily constructed by means of recursion relations. It is shown that complete sets of states can be projected from corresponding quasi-particle states and that such states retain many of the properties of the quasi-particle states from which they derive. It is also shown that number projection can be used to construct a complete set of orthogonal states classified by generalized seniority for any nucleus.