期刊
PHYSICAL REVIEW B
卷 85, 期 2, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.85.024534
关键词
-
资金
- ICAM
- NSF-DMR [0645461, 0906953]
- NSF [1066293]
- DAAD (PPP USA) [50750339]
- Direct For Mathematical & Physical Scien [0645461] Funding Source: National Science Foundation
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [906953] Funding Source: National Science Foundation
- Division Of Materials Research [0645461] Funding Source: National Science Foundation
Starting from a microscopic itinerant model, we derive and analyze the effective low-energy model for collective magnetic excitations in the iron pnictides. We show that the stripe magnetic order is generally preempted by an Ising-nematic order, which breaks C-4 lattice symmetry but preserves O(3) spin-rotational symmetry. This leads to a rich phase diagram as function of doping, pressure, and elastic moduli, displaying split magnetic and nematic tricritical points. The nematic transition may instantly bring the system to the verge of a magnetic transition, or it may occur first, being followed by a magnetic transition at a lower temperature. In the latter case, the preemptive nematic transition is accompanied by either a jump or a rapid increase of the magnetic correlation length, triggering a pseudogap behavior associated with magnetic precursors. Furthermore, due to the distinct orbital character of each Fermi pocket, the nematic transition also induces orbital order. We compare our results to various experiments, showing that they correctly address the changes in the character of the magnetostructural transition across the phase diagrams of different compounds, as well as the relationship between the orthorhombic and magnetic order parameters.
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