Effective Hamiltonian for FeAs based superconductors
| dc.creator | Manousakis, Efstratios | |
| dc.creator | Ren, Jun | |
| dc.creator | Meng, Sheng | |
| dc.creator | Kaxiras, Efthimios | |
| dc.date | 2008-06-20 | |
| dc.date | 2008-11-20 | |
| dc.date.accessioned | 2026-07-07T10:19:20Z | |
| dc.date.available | 2026-07-07T10:19:20Z | |
| dc.description | The recently discovered FeAs-based superconductors show intriguing behavior and unusual dynamics of electrons and holes which occupy the Fe $d$-orbitals and As $4s$ and $4p$ orbitals. Starting from the atomic limit, we carry out a strong coupling expansion to derive an effective hamiltonian that describes the electron and hole behavior. The hopping and the hybridization parameters between the Fe $d$ and As $s$ and $p$-orbitals are obtained by fitting the results of our density-functional-theory calculations to a tight-binding model with nearest-neighbor interactions and a minimal orbital basis. We find that the effective hamiltonian, in the strong on-site Coulomb repulsion limit, operates on three distinct sub-spaces coupled through Hund's rule. The three sub-spaces describe different components (or subsystems): (a) one spanned by the $d_{x^2-y^2}$ Fe orbital; (b) one spanned by the degenerate atomic Fe orbitals $d_{xz}$ and $d_{yz}$; and (c) one spanned by the atomic Fe orbitals $d_{xy}$ and $d_{z^2}$. Each of these Hamiltonians is an extended t-t'-J-J' model and is characterized by different coupling constants and filling factors. For the case of the undoped material the second subspace alone prefers a ground state characterized by a spin-density-wave order similar to that observed in recent experimental studies, while the other two subspaces prefer an antiferromagnetic order. We argue that the observed spin-density-wave order minimizes the ground state energy of the total hamiltonian. | |
| dc.description | 11 pages, 6 figures | |
| dc.identifier | https://arxiv.org/abs/0806.3432 | |
| dc.identifier | http://arxiv.org/abs/0806.3432 | |
| dc.identifier | Phys. Rev. B 78, 205112 (2008) | |
| dc.identifier | doi:10.1103/PhysRevB.78.205112 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/174470 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Superconductivity | |
| dc.title | Effective Hamiltonian for FeAs based superconductors | |
| dc.type | text |