Off-diagonal long-range order in the BCS
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Marvin E Rensink
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Article
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1967
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Elsevier Science
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English
โ 339 KB
The two-particle reduced density matrix p2 is analyzed for a system of electrons described by the BCS ground state. The existence of off-diagonal longrange order in pZ is demonstrated by explicit calculation of its matrix elements. It is shown that pz has one eigenvalue proportional to N where N is