Open AccessSU(2) AND GLAUBER COHERENT STATES OF COOPER PAIRS IN SUPERCONDUCTOR——STUDIES OF THE QUANTUM CHARACTERS OF COOPER PAIRS AND JOSEPHSON SUPERFLUIDITY
Author(s) -
Huang Hong-Bin
Publication year - 1991
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.40.1402
Subject(s) - cooper pair , physics , coherent states , superfluidity , josephson effect , superconductivity , quantum mechanics , condensed matter physics , glauber , wave function , quantum , scattering
It is shown, using the quasi-spin operator, that the BCS superconducting ground-state wave function is the direct product of single Cooper-pair SU(2) coherent state wave functions, and in certain conditions, is SU(2) coherent state wave function of the Cooper-pair system. If two superconductors, both in BCS ground state, are coupled together, the coupled system is also in SU(2) coherent state. Under the contraction of group SU(2) to harmonic-oscillator group, the SU(2) coherent states contract to Glauber coherent states. The quantum fluctuations, distributions, and second correlations of Cooper pairs and Josephson superfluidity in the two cases are discussed.