Motivated by recent experiments on heavy fermion materials CeCu2Si2 and UBe13, we develop a framework to capture generic properties of multiband superconductors with strong Pauli paramagnetic effect (PPE). In contrast to the single band case, the upper critical field Hc2 can remain a second-order transition even for strong PPE cases. The expected first-order transition is hidden inside Hc2 and becomes a crossover due to the interplay of multibandness. The present theory based on full self-consistent solutions of the microscopic Eilenberger theory explains several mysterious anomalies associated with the crossover and the "empty" vortex core state which is observed by recent STM experiment on CeCu2Si2.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jul 6 2015|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics