2011/08/31 by Qinlong Luo, Andrew Nicholson, J. Riera +5
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Corporate Taxation and Avoidance #Ferromagnetism #Hubbard model #Iron-based superconductors research #Magnetic moment #Mott insulator #Phase (matter) #Phase diagram #Physics #Quantum mechanics #Rare-earth and actinide compounds #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.84.140506
published as Phys. Rev. B 84, 140506(R) (2011) · 4 pages, 4 figures. Additional references are added
arxiv created 2011/09/08 · openalex publication_date 2011/10/21 · arxiv updated 2012/06/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Motivated by the recent discovery of Fe-based superconductors close to an antiferromagnetic insulator in the experimental phase diagram, here the five-orbital Hubbard model (without lattice distortions) is studied using the real-space Hartree-Fock approximation, employing a 10\ifmmode×\else\texttimes\fi10 Fe cluster with Fe vacancies in a √(5)\ifmmode×\else\texttimes\fi√(5) pattern. Varying the Hubbard and Hund couplings, and at electronic density n=6.0, the phase diagram contains an insulating state with the same spin pattern as observed experimentally, involving 2\ifmmode×\else\texttimes\fi2 ferromagnetic plaquettes coupled with one another antiferromagnetically. The presence of local ferromagnetic tendencies is in qualitative agreement with Lanczos results for the three-orbital model also reported here. The magnetic moment \ensuremath∼3\ensuremathμB/Fe is in good agreement with experiments. Several other phases are also stabilized in the phase diagram, in agreement with recent calculations using phenomenological models.