Paramagnetic Effects on the Vortex Lattice of the Unconventional Superconductor CeCoIn_5

TL;DR

This paper analyzes how paramagnetic effects influence the vortex lattice in the unconventional superconductor CeCoIn_5, revealing field-dependent form factors consistent with experimental observations and emphasizing the role of spin interactions in high-field superconductivity.

Contribution

It introduces a generalized Clem variational approach to model the magnetic field distribution considering paramagnetic effects in d-wave superconductors.

Findings

Form factor increases with field and then decreases near H_c2.

Paramagnetic interactions significantly affect vortex lattice structure.

Results align with recent experimental observations in CeCoIn_5.

Abstract

We expose an analysis of the magnetic field distribution in the Abrikosov lattice of high-kappa superconductors with d-wave pairing in the case where the critical field is mainly determined by the Pauli limit and the superfluid currents mainly come from the paramagnetic interaction of electron spins with the local magnetic field. The result found in frame of the generalized Clem variational approach is compatible with the recent observation that the form factor in CeCoIn_5 increases with increasing field and then decreases at the approach of H_c2. (A. D. Bianchi et al., Science vol. 319, 177 (2008)).