When:
Thursday, May 17, 2018
4:00 PM - 5:30 PM CT
Where: Technological Institute, F160, 2145 Sheridan Road, Evanston, IL 60208 map it
Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students
Contact:
Cristian Pennington
Group: Physics and Astronomy Condensed Matter Physics Seminars
Category: Academic
Dr. Kok Wee Song- Materials Science Division, Argonne National Laboratory
Title: Landau-quantization effects in the superconducting transitions of layered materials
Abstract: Superconducting transition in a magnetic field is a long-standing fundamental problem. The standardly-used quasiclassical approach is a powerful tool to tackle this problem. Although the electrons’ orbital-quantization effects are neglected, this approach still yields accurate results for most conventional superconductors. However, this method breaks down in the quantum limit where the carriers’ Landau quantum number is very low. Such situation is realized in materials with shallow bands such as iron-based superconductors. Motivated by this, we investigate the pairing instabilities of a multiband layered superconductor taking the Landau quantization into account exactly. Typically, the quantization effects in the shallow band strongly influence the pairing instabilities and may lead to reentrant superconductivity at high magnetic fields. Furthermore, the interplay between orbital-quantization and Zeeman effects strongly promotes the formation of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states which Cooper pairs have nonzero total momentum along the magnetic field. Most intriguingly, such quantum effects in the FFLO states persist even in the not-too-shallow-band regime where the quasiclassical approximation is supposed to work well.
Host: Jim Sauls