Na2IrO3 as a Molecular Orbital Crystal

被引：165

作者：

Mazin, I. I. ^{[1
]}

Jeschke, Harald O. ^{[2
]}

Foyevtsova, Kateryna ^{[2
]}

Valenti, Roser ^{[2
]}

Khomskii, D. I. ^{[3
]}

机构：

[1] USN, Res Lab, Washington, DC 20375 USA

[2] Goethe Univ Frankfurt, Inst Theoret Kernphys, D-60438 Frankfurt, Germany

[3] Univ Cologne, Inst Phys 2, D-50937 Cologne, Germany

来源：

PHYSICAL REVIEW LETTERS | 2012年 / 109卷 / 19期

关键词：

Sodium compounds - Electronic structure - Molecular orbitals - Density functional theory;

D O I：

10.1103/PhysRevLett.109.197201

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Contrary to previous studies that classify Na2IrO3 as a realization of the Heisenberg-Kitaev model with a dominant spin-orbit coupling, we show that this system represents a highly unusual case in which the electronic structure is dominated by the formation of quasimolecular orbitals (QMOs), with substantial quenching of the orbital moments. The QMOs consist of six atomic orbitals on an Ir hexagon, but each Ir atom belongs to three different QMOs. The concept of such QMOs in solids invokes very different physics compared to the models considered previously. Employing density functional theory calculations and model considerations we find that both the insulating behavior and the experimentally observed zigzag antiferromagnetism in Na2IrO3 naturally follow from the QMO model.

引用

页数：5

共 14 条

[1] Spin-orbital locking, emergent pseudo-spin and magnetic order in honeycomb lattice iridates [J].