Free energy of a layered superconductor with ξ <d is calculated in a parallel magnetic field by means of the Gor'kov equations, where ξ is a coherence length perpendicular to the layers and d is an interlayer distance. The free energy is shown to differ from that in the textbook Lawrence-Doniach model at high fields, where the Meissner currents are found to create an unexpected positive magnetic moment due to shrinking of the Cooper pair "sizes" by a magnetic field. This paramagnetic intrinsic Meissner effect in a bulk is suggested to detect, by measuring in-plane torque, the upper critical field and magnetization in layered organic and high- Tc superconductors, as well as in superconducting superlattices.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jul 23 2008|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics