TY - JOUR
T1 - Magnetic states of the five-orbital Hubbard model for one-dimensional iron-based superconductors
AU - Luo, Qinlong
AU - Foyevtsova, Kateryna
AU - Samolyuk, German D.
AU - Reboredo, Fernando
AU - Dagotto, Elbio
PY - 2014/7/22
Y1 - 2014/7/22
N2 - The magnetic phase diagrams of models for quasi-one-dimensional compounds belonging to the iron-based-superconductor family are presented. The five-orbital Hubbard model and the real-space Hartree-Fock approximation are employed, supplemented by density functional theory to obtain the hopping amplitudes. Phase diagrams are constructed by varying the Hubbard U and Hund J couplings at zero temperature. The study is carried out at electronic density (electrons per iron) n=5.0, which is of relevance for the already-known material TlFeSe2, and also at n=6.0, where representative compounds still need to be synthesized. At n=5.0 there is a clear dominance of staggered spin order along the chain direction. At n=6.0 and with the realistic Hund coupling J/U=0.25, the phase diagram is far richer, including a variety of "block" states involving ferromagnetic clusters that are antiferromagnetically coupled, in qualitative agreement with recent density matrix renormalization group calculations for the three-orbital Hubbard model in a different context. These block states arise from the competition between ferromagnetic order (induced by double exchange and prevailing at large J/U) and antiferromagnetic order (dominating at small J/U). The density of states and orbital compositions of the many phases are also provided.
AB - The magnetic phase diagrams of models for quasi-one-dimensional compounds belonging to the iron-based-superconductor family are presented. The five-orbital Hubbard model and the real-space Hartree-Fock approximation are employed, supplemented by density functional theory to obtain the hopping amplitudes. Phase diagrams are constructed by varying the Hubbard U and Hund J couplings at zero temperature. The study is carried out at electronic density (electrons per iron) n=5.0, which is of relevance for the already-known material TlFeSe2, and also at n=6.0, where representative compounds still need to be synthesized. At n=5.0 there is a clear dominance of staggered spin order along the chain direction. At n=6.0 and with the realistic Hund coupling J/U=0.25, the phase diagram is far richer, including a variety of "block" states involving ferromagnetic clusters that are antiferromagnetically coupled, in qualitative agreement with recent density matrix renormalization group calculations for the three-orbital Hubbard model in a different context. These block states arise from the competition between ferromagnetic order (induced by double exchange and prevailing at large J/U) and antiferromagnetic order (dominating at small J/U). The density of states and orbital compositions of the many phases are also provided.
UR - http://www.scopus.com/inward/record.url?scp=84904876363&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.90.035128
DO - 10.1103/PhysRevB.90.035128
M3 - Article
AN - SCOPUS:84904876363
SN - 1098-0121
VL - 90
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 3
M1 - 035128
ER -