We analyze the combined effect of orbital and Pauli depairing on the superconducting state, and apply the results to the heavy fermion CeCoIn 5. We find that (a) standard extrapolation based on the slope of Hc2 (T) in the vicinity of the transition temperature does not always give accurate values of the orbital upper critical field; (b) critical value of the Maki parameter, α, which determines onset of the first order transition, depends on the Fermi surface shape and the symmetry of the gap and is α* ≈ 3 for CeCoIn5; and (c) the anisotropy of the thermodynamic and transport coefficients in the low-temperature, low-field part of the phase diagram is essentially insensitive to the Zeeman field and can be used to determine the nodal directions in Pauli-limited superconductors. The latter result confirms the finding of the d x2 - y2 order parameter CeCoIn5. © 2010 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review B - Condensed Matter and Materials Physics
Vorontsov, A., & Vekhter, I. (2010). Vortex state in d -wave superconductors with strong paramagnetism: Transport and specific heat anisotropy. Physical Review B - Condensed Matter and Materials Physics, 81 (9) https://doi.org/10.1103/PhysRevB.81.094527