Events at Physics |
Events on Monday, November 21st, 2011
- Plasma Physics (Physics/ECE/NE 922) Seminar
- TBD
- Time: 12:05 pm
- Place: 2317 Engineering Hall
- Speaker: John Canik, ORNL
- Condensed Matter Theory Group Seminar
- Spin resonance in Fe-based superconductors
- Time: 4:30 pm
- Place: 5310 Chamberlin
- Speaker: Saurabh Maiti, UW-Madison
- Abstract: Fe-based superconductors(FeSCs) and cuprates are often held as prime candidates for study that can lead to the understanding of the unconventional high Tc superconductivity. In this talk, I will briefly mention the motivation behind looking for spin resonance in unconventional superconductors. I will mention some the similarities and differences that are seen in experiments in these two family of compounds. Unlike in the cuprates where people agree on the d-wave symmetry, FeSCs are much more interesting. Different symmetries and structures are possible for the gap structure in these materials. Observation of a spin resonance indicates presence of on order parameter that needs to flip its sign in some parts of the Fermi-surface. Experiments in FeSC actually see a relatively broad peak (unlike in cuprates) and this has been argued by some groups to be due to a 'sign preserving' order parameter contrary to the popular 'sign-flipping' order parameter in FeSCs. In this talk I will present our resolution of the conflict and explain how the experimental observations can be understood by accounting for nodes in the gap, impurity scattering and Fermi-surface geometry.
- Host: Perkins