Ginzburg-Landau theory for multiband superconductors : Microscopic derivation

Titelangaben

Orlova, N. V. ; Shanenko, A. A. ; Milošević, M. V. ; Peeters, F. M. ; Vagov, Alexei ; Axt, Vollrath Martin:
Ginzburg-Landau theory for multiband superconductors : Microscopic derivation.
In: Physical Review B. Bd. 87 (2013) Heft 13 . - 134510.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.87.134510

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Abstract

A procedure to derive the Ginzburg-Landau (GL) theory from the multiband BCS Hamiltonian is developed in a general case with an arbitrary number of bands and arbitrary interaction matrix. It combines the standard Gor'kov truncation and a subsequent reconstruction in order to match accuracies of the obtained terms. This reconstruction recovers the phenomenological GL theory as obtained from the Landau model of phase transitions but offers explicit microscopic expressions for the relevant parameters. Detailed calculations are presented for a three-band system treated as a prototype multiband superconductor. It is demonstrated that the symmetry in the coupling matrix may lead to the chiral ground state with the phase frustration, typical for systems with broken time-reversal symmetry.