期刊
NATURE PHYSICS
卷 5, 期 8, 页码 555-560出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/NPHYS1336
关键词
-
资金
- US National Science Foundation [DMR-0756568]
- US Department of Energy
- Division of Materials Science
- DOE [DE-FG02-05ER46202]
- Chinese Academy of Sciences
- Natural Science Foundation of China, the Chinese Academy of Sciences and the Ministry of Science and Technology of China
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [0756568] Funding Source: National Science Foundation
- U.S. Department of Energy (DOE) [DE-FG02-05ER46202] Funding Source: U.S. Department of Energy (DOE)
Antiferromagnetism is relevant to high-temperature (high-T-c) superconductivity because copper oxide and iron arsenide superconductors arise from electron- or hole-doping of their antiferromagnetic parent compounds(1-6). There are two broad classes of explanation for antiferromagnetism: in the 'local moment' picture, appropriate for the insulating copper oxides(1), antiferromagnetic interactions are well described by a Heisenberg Hamiltonian(7,8); whereas in the 'itinerant model', suitable for metallic chromium, antiferromagnetic order arises from quasiparticle excitations of a nested Fermi surface(9,10). There has been contradictory evidence regarding the microscopic origin of the antiferromagnetic order in iron arsenide materials(5,6), with some favouring a localized picture(11-15) and others supporting an itinerant point of view(16-20). More importantly, there has not even been agreement about the simplest effective ground-state Hamiltonian necessary to describe the antiferromagnetic order(21-25). Here, we use inelastic neutron scattering to map spin-wave excitations in CaFe2As2 (refs 26, 27), a parent compound of the iron arsenide family of superconductors. We find that the spin waves in the entire Brillouin zone can be described by an effective three-dimensional local-moment Heisenberg Hamiltonian, but the large in-plane anisotropy cannot. Therefore, magnetism in the parent compounds of iron arsenide superconductors is neither purely local nor purely itinerant, rather it is a complicated mix of the two.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据