International Journal of Advanced Applied Physics Research  (Special Issue 1)
 Space-group approach to the wavefunction of a Cooper pair: Nodal structure and additional quantum numbers for Sr2RuO4 and UPt3 International Journal of Advanced Applied Physics Research
Pages 48-56

V.G. Yarzhemsky

Published: 28 January 2016
 Induced representation method and Mackey theorem on symmetrized squares were applied to construct zero-total-momentum two-electron states in solids, corresponding to Cooper pairs in unconventional superconductors. In this approach the structure of two-electron states depends on the position of one-electron wave vector in a single-electron Brillouin zone. It is shown, that the decomposition of total two-electron basis set results in repeating multidimensional irreducible representations. It is obtained, that in order to label repeating irreducible representation two additional quantum numbers are required: irreducible representation of wave vector group for symmetry planes and directions and quantum numbers on an intermediate group for a general point in a Brillouin zone. Theoretical results are applied to unconventional superconductors UPt3 and Sr2RuO4.
 group theory, induced representations, Mackey theorem, unconventional superconductors, nodal superconductors, triplet superconductors, Sr2RuO4, UPt3.