Condensed Matter Seminar: Magnetic Properties of Model Hamiltonians for the Iron-based Superconductors

After a brief introduction to iron based high temperature superconductivity, this presentation will focus on two recent results: (1) the unexpected complexity of magnetic states found in real-space Hartree-Fock studies of Se-based compounds when in the presence of regularly spaced iron vacancies and also in the case of two-leg ladders, and (2) the much studied spin nematic state and its diverging susceptibility above the critical temperature T_S analyzed from the perspective of Monte Carlo simulations of the spin fermion model. The presentation is based on the following publications:P. Dai, JP Hu, and E.D., Nat. Phys. 8, 709 (2012); E.D., RMP 85, 849 (2013);Q. Luo et al., PRB 84, 140506(R) (2011); Q. Luo et al., PRB 87, 024404 (2013);S. Liang et al., PRL 111, 047004 (2013); and S. Liang et al., arXiv:1405.6395