Magnetic phase diagram of a fiveorbital Hubbard model in the realspace HartreeFock approximation varying the electronic density
Abstract
Using the realspace HartreeFock approximation, the magnetic phase diagram of a fiveorbital Hubbard model for the ironbased superconductors is studied varying the electronic density n in the range from five to seven electrons per transition metal atom. The Hubbard interaction U is also varied, at a fixed Hund coupling J /U=0.25. Several qualitative trends and a variety of competing magnetic states are observed. At n =5, a robust Gtype antiferromagnetic insulator is found, in agreement with experimental results for BaMn2As2. As n increases away from 5, magnetic states with an increasing number of nearestneighbors ferromagnetic links become energetically stable. This includes the wellknown Ctype antiferromagnetic state at n =6, the Ephase known to exist in FeTe, and also a variety of novel states not found yet experimentally, some of them involving blocks of ferromagnetically oriented spins. Regions of phase separation, as in Mn oxides, have also been detected. Comparison to previous theoretical investigations indicate that these qualitative trends may be generic characteristics of phase diagrams of multiorbital Hubbard models.
 Publication:

Physical Review B
 Pub Date:
 January 2014
 DOI:
 10.1103/PhysRevB.89.045115
 arXiv:
 arXiv:1308.3426
 Bibcode:
 2014PhRvB..89d5115L
 Keywords:

 74.70.Xa;
 71.27.+a;
 Strongly correlated electron systems;
 heavy fermions;
 Condensed Matter  Superconductivity;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 9 pages, 6 figures and 3 tables