Magnetism and its microscopic origin in iron-based high-temperature superconductors
by Pengcheng Dai, Jiangping Hu, Elbio Dagotto
The authors highlight
- the diversity of materials and types of magnetic order in the parent compounds
- just giving a theoretical description of the parent compounds is a challenge
- that these materials are in an intermediate coupling (moderately? correlated) regime where weak-coupling treatments are inadequate
- there are local magnetic moments at room temperature, which is well above most of the magnetic ordering temperatures
- how poorly understood the multi-band Hubbard model is, even at half filling
The phase diagram below is based on Hartree-Fock theory (which surely is quite inadequate). J_H is the Hund's rule coupling. The "physical region" is probably the parameter regime of the pnictides.
I am interested to know how this diagram compares to DMFT (dynamical mean-field theory) and DMRG studies on ladders.