Eilenberger theory and London theory for transverse components of flux line lattice form factors in uniaxial superconductors

TL;DR

This paper compares Eilenberger and London theories to analyze the magnetic field orientation dependence of flux line lattice form factors in uniaxial superconductors, considering anisotropy and pairing symmetry effects.

Contribution

It introduces a comparative analysis of Eilenberger and London theories for flux line lattice form factors, including a new cutoff function for the extended London theory.

Findings

Differences between s-wave and d-wave pairings are discussed.

The cutoff function in the extended London theory is characterized.

The methods help interpret small angle neutron scattering data.

Abstract

We theoretically study the magnetic field orientation dependence of longitudinal and transverse flux line lattice form factors in uniaxial superconductors with anisotropy ratio corresponding to YBa_2_Cu_3_O_{7-delta}. We discuss influences of the anisotropy ratio of coherence length, and differences between the s-wave and the d_{x^2-y^2}-wave pairings. The calculations are performed by two methods, the Eilenberger theory and the London theory comparatively, and we study the cutoff function of the extended London theory, which will be helpful in the analysis of the small angle neutron scattering in the vortex states.