Discontinuous Superconducting Transitions in the Paramagnetic limit: a Non-Perturbative approach


Discontinuous Superconducting Transitions in the Paramagnetic limit: a Non-Perturbative approach

Maniv, T.; Zhuravlev, V.; Wosnitza, J.

The unusual superconducting (SC) phase transitions occuring under competing orbital and spin pair breaking, which characterize clean strongly type-II superconductors at low temperatures, are investigated within a non-perturbative approach, which avoides the difficulties encountered in various perturbative approaches and enables comparison with recent experimental data. It is shown that in a 3D system with strong spin-splitting, a spatial (FFLO) modulation of the order parameter along the magnetic-field direction preserves the continuous nature of the SC transition. However, at a magnetic field slightly below Hc2 the FFLO state becomes unstable, transforming discontinuously into a uniform SC state via a first-order phase transition. Our calculation shows that the entropy jump at the first-order phase transition is siginificantly larger than its total variation in the continuous region between the two transitions, in agreement with recent thermal-conductivity measurements performed on the heavy-fermion compound URu2Si2.

  • Open Access Logo Journal of Physics: Conference Series 150(2009), 052151

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Publ.-Id: 12658