90 degrees reorientation in the vortex lattice of borocarbide superconductors

Abstract

We explain 90 degrees reorientation in the vortex lattice of borocarbide superconductors on the basis of a phenomenological extension of the nonlocal London model that takes full account of the symmetry of the system. Microscopic mechanisms that could generate the correction terms are analyzed. We show that for any dispersion relation and longitudinal phonon-electron pairing mechanism the relevant quantity is strongly suppressed. Possible phenomenological interaction terms providing the effect are studied.