Magnetic states of the two-leg-ladder alkali metal iron selenides AFe2Se3

• Autores: Luo, Qinlong; Nicholson, Andrew; Rincon, Julián; Liang, Shuhua; Riera, Jose Alejandro; Alvarez, Gonzalo; Wang, Limin; Ku, Wei; Samolyuk, German D.; Moreo, Adriana; Dagotto, Elbio
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Superconductividad; Magnetismo; Seleniuros de Hierro; Hubbard
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Recent neutron scattering experiments addressing the magnetic state of the two-leg-ladder selenide compound BaFe2Se3 have unveiled a dominant spin arrangement involving ferromagnetically ordered 2×2 iron superblocks, that are antiferromagnetically coupled among them (the ``block-AFM''state). Using the electronic five-orbital Hubbard model first-principles techniques to calculate the electronic hopping amplitudes between irons, and the real-space Hartree-Fock approximation to handle the many-body effects, here it is shown that the exotic block-AFM state is indeed stable at realistic electronic densities close to n∼6.0. Another state with parallel spins along the rungs and antiparallel along the legs of the ladders (the “CX” state) is close in energy. This state becomes stable in other portions of the phase diagrams, such as with hole doping, as also found experimentally via neutron scattering applied to KFe2Se3. In addition, the present study unveils other competing magnetic phases that could be experimentally stabilized by varying either n chemically or the electronic bandwidth by pressure. Similar results were obtained using two-orbital models, studied here via Lanczos and density-matrix renormalization group (DMRG) techniques. A comparison of the results obtained with the realistic selenides hopping amplitudes for BaFe2Se3 against those found using the hopping amplitudes for pnictides reveals several qualitative similarities, particularly at intermediate and large Hubbard couplings.
Fil: Luo, Qinlong. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Nicholson, Andrew. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Rincon, Julián. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Liang, Shuhua. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Riera, Jose Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentina
Fil: Alvarez, Gonzalo. Oak Ridge National Laboratory. Computer Science and Mathematics Division and Center for Nanophase Materials Sciences; Estados Unidos
Fil: Wang, Limin. Brookhaven National Laboratory; Estados Unidos
Fil: Ku, Wei. Brookhaven National Laboratory; Estados Unidos. State University Of New York; Estados Unidos
Fil: Samolyuk, German D.. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Moreo, Adriana. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos
Fil: Dagotto, Elbio. University Of Tennessee; Estados Unidos. Oak Ridge National Laboratory. Materials Science and Technology Division; Estados Unidos