Kamakura Nozomu
Institute of Materials Structure Science, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan.
J Phys Condens Matter. 2009 Jan 21;21(3):035601. doi: 10.1088/0953-8984/21/3/035601. Epub 2008 Dec 11.
Itinerant ferromagnetism derived from e(g) and t(2g) states has been studied by the Gutzwiller variational method based on the two-band Hubbard model. The analysis shows that the magnetization value that depends on the orbital reflects strength of renormalization for each band. As a result, the magnetization of the 3d(t(2g)) band, which is more strongly renormalized in the calculation, has a larger value than that of the 3d(e(g)) band. By changing the atomic interaction and projected orbital density of states (DOS), we have discussed general tendencies that the magnetizations by the e(g) and t(2g) states are determined by the relative intensities of the projected orbital DOS at the Fermi energy, the renormalized kinetic energies relative to U, and stability of atomic multielectron configuration states. The result indicates that increases in Coulomb interaction U and the portion of Hund's coupling J in the atomic interaction lead to balanced magnetizations between the two states. Variation in the above factors can generate a variety of spin-dependent electronic structures near the Fermi energy in 3d transition metal ferromagnets.
基于双带Hubbard模型，利用Gutzwiller变分方法研究了由e(g)和t(2g)态衍生的巡游铁磁性。分析表明，依赖于轨道的磁化值反映了每个能带重整化的强度。结果，在计算中重整化更强的3d(t(2g))能带的磁化值比3d(e(g))能带的磁化值更大。通过改变原子相互作用和投影态密度（DOS），我们讨论了一般趋势，即e(g)和t(2g)态的磁化由费米能处投影轨道DOS的相对强度、相对于U的重整化动能以及原子多电子组态态的稳定性决定。结果表明，库仑相互作用U的增加以及原子相互作用中洪德耦合J的比例导致两种状态之间的磁化平衡。上述因素的变化可以在3d过渡金属铁磁体的费米能附近产生各种自旋相关的电子结构。
