Ferromagnetic zigzag chains and properties of the charge ordered perovskite manganites
| dc.creator | Solovyev, I. V. | |
| dc.date | 2003-07-16 | |
| dc.date.accessioned | 2026-07-07T06:29:43Z | |
| dc.date.available | 2026-07-07T06:29:43Z | |
| dc.description | The low-temperature properties of the so-called ''charge ordered'' state in 50% doped perovskite manganites are described from the viewpoint of the magnetic spin ordering. In these systems, the zigzag antiferromagnetic ordering, combined with the double-exchange physics, effectively divides the whole sample into the one-dimensional ferromagnetic zigzag chains and results in the anisotropy of electronic properties. The electronic structure of one such chain is described by an effective 3$\times$3 Hamiltonian in the basis of Mn($3de_g$) orbitals. We treat this problem analytically and consider the following properties: (i) the nearest-neighbor magnetic interactions; (ii) the distribution of the Mn($3de_g$) and Mn($4p$) states near the Fermi level, and their contribution to the optical conductivity and the resonant x-ray scattering near the Mn $K$-absorption edge. We argue that the anisotropy of magnetic interactions in the double-exchange limit, combined with the isotropic superexchange interactions, readily explains both the local and the global stability of the zigzag antiferromagnetic state. The two-fold degeneracy of $e_g$ levels plays a very important role in the problem and explains the insulating behavior of the zigzag chain, as well as the appearance of the orbital ordering in the double-exchange model. Importantly, however, the charge ordering itself is expected to play only a minor role and is incompatible with the ferromagnetic coupling within the chain. We also discuss possible effects of the Jahn-Teller distortion and compare the tight-binding picture with results of band structure calculations in the local-spin-density approximation. | |
| dc.description | 35 pages, 8 figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0307382 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0307382 | |
| dc.identifier | Phys. Rev. B 63, 174406 (2001) | |
| dc.identifier | doi:10.1103/PhysRevB.63.174406 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/98135 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Materials Science | |
| dc.title | Ferromagnetic zigzag chains and properties of the charge ordered perovskite manganites | |
| dc.type | text |