Symmetry in Fe-based Superconductors - From Magnetism and Lattice Distortion to Phase Transitions and Domains
| Date/Time: | Monday, 12 Oct 2015 from 4:10 pm to 5:00 pm |
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| Location: | Physics 0003 |
| Phone: | 515-294-5441 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
Symmetry and symmetry invariants are helpful concepts in understanding complex behavior in condensed matter physics. Analyzing ordering phenomena by the underlying symmetry allows often finding primary models and basic relations between different states. In this presentation I will describe the relation between magnetism, lattice and electronic structure in the class of Fe-based superconductors using these concepts. After an introduction to characteristic behavior and phase diagrams I will focus on the relation between magnetic ordering, lattice distortion and superconductivity and introduce the nematic model. In the related phase transitions, domains develop with a regular network of domain walls separating the same state of matter in different orientations as consequence of broken symmetry elements. I will demonstrate how we experimentally characterize and modify these domain structures, how they influence physical properties and how special relations between different states yield even more complex domain patterns in the case of Co-substituted CaFe2As2 single crystals.