Microscopic derivation of two-component Ginzburg-Landau model and conditions of its applicability in two-band systems
Abstract
We report a microscopic derivation of two-component Ginzburg-Landau (GL) field theory and the conditions of its validity in two-band superconductors. We also investigate the conditions when microscopically derived or phenomenological GL models fail and one should resort to a microscopic description. We show that besides being directly applicable at elevated temperatures, a version of a minimal two-component GL theory in certain cases also gives an accurate description of certain aspects of a two-band system, even substantially far from Tc. This shows that a two-component GL model can be used for addressing a wide range of questions in multiband systems, in particular vortex physics and magnetic response. We also argue that a single Ginzburg-Landau parameter cannot in general characterize the magnetic response of multiband systems.
- Publication:
-
Physical Review B
- Pub Date:
- April 2012
- DOI:
- 10.1103/PhysRevB.85.134514
- arXiv:
- arXiv:1110.1593
- Bibcode:
- 2012PhRvB..85m4514S
- Keywords:
-
- 74.20.Fg;
- 74.25.Ha;
- BCS theory and its development;
- Magnetic properties;
- Condensed Matter - Superconductivity
- E-Print:
- 10 pages, 3 figures, in print with PRB