Enhanced nematic and antiferromagnetic phases in the spin-fermion model for strained iron pnictides
Enhanced nematic and antiferromagnetic phases in the spin-fermion model for strained iron pnictides
复制标题
应变铁磷族元素自旋费米子模型中增强的向列相和反铁磁相
DOI：
10.1088/1367-2630/17/1/013011
复制
发表时间：
2015-01-09
影响因子：
3.3
通讯作者：
Ren, Zhifeng
中科院分区：
文献类型：
--
作者：
Qin, Minghui;Dong, Shuai;Ren, Zhifeng
研究了非掺杂三轨道自旋费米子模型中各向异性超交换和Fe-Fe跳跃对相变的影响，以了解实验报道的BaFe 2As 2中的应变效应。Monte Carlo模拟的相图表明，随着各向异性的增加，共线的反铁磁和反铁磁相变都向高温方向移动，这与实验结果定性一致。因此，各向异性超交换和Fe-Fe跳跃被认为是负责的转变温度的变化与单轴应力BaFe_2As_2。此外，我们还观察到共线反铁磁序的90度旋转，并伴随着费米面上的轨道占据反转，当超交换各向异性的符号发生变化时，进一步支持了先前通过第一性原理计算的预测。
The effects of anisotropic superexchange and Fe-Fe hoppings on phase transitions in the undoped three-orbital spin-fermion model are investigated to understand the experimentally reported strain effect in BaFe2As2. Monte Carlo simulated phase diagrams show that both the collinear antiferromagnetic and nematic transitions shift toward high temperature with the increasing magnitude of anisotropies, qualitatively consistent with experimental observation. Thus, both the anisotropic superexchange and Fe-Fe hoppings are suggested to be responsible for the variation of the transition temperatures of BaFe2As2 with uniaxial stress. In addition, we observed a 90 degree rotation of the collinear antiferromagnetic order, accompanied with a reversal of the orbital occupancy at the Fermi surface when the sign of the superexchange anisotropy changes, further supporting previous predictions by first principles calculation.