Magnetic regions inside a superconductor and its effects on the vortex matter

✍ Scribed by Mauro M. Doria

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 692 KB
• Volume: 404
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2003.11.049

✦ Synopsis

A superconductor with magnetic regions inside, forming an orthorhombic lattice of rigidly oriented magnetic moments, is investigated using a Ginzburg-Landau free energy expansion that naturally provides a unified view of both superconducting and non-superconducting regions. Point like magnetic moments are inside insulating regions, chosen to be either layers or spheres, of coherence length size. Thus an insulator-superconductor multi-layered system, and a superconductor with an orthorhombic lattice of spherical pinning centers are under investigation here. The rigidly oriented magnetic moments form two ground states, a ferromagnetic and a mixed one, namely, antiferromagnetic along the direction perpendicular to the moments and ferromagnetic inside the sheets containing the moments. A spontaneous vortex phase is found to exist for all systems above a critical magnetic moment value.