Quantum transitions of nematic phases in a spin-1 bilinear-biquadratic model and their implications for FeSe
Quantum transitions of nematic phases in a spin-1 bilinear-biquadratic model and their implications for FeSe
复制标题
spin-1 双线性双二次模型中向列相的量子跃迁及其对 FeSe 的影响
DOI：
10.1103/physrevresearch.2.023359
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发表时间：
2020
影响因子：
4.2
通讯作者：
Si Qimiao
中科院分区：
文献类型：
--
作者：
Hu Wen-Jun;Lai Hsin-Hua;Gong Shou-Shu;Yu Rong;Dagotto Elbio;Si Qimiao
自发现以来，铁基超导性一直被认为是在反铁磁序附近发展的，但这种范式在铁硫属化物FeSe中失败了，其单层版本保持着铁基超导体中最高超导转变温度的记录。FeSe在非磁性的同时表现出向列有序（自发破缺的晶格旋转对称性）这一令人震惊的谜题，导致了几种关于其起源的相互竞争的提议，要么是3d $电子的轨道自由度，要么是以受抑磁性形式的自旋物理学。在这里，我们认为，在压力下的FeSe的相图可以定性描述的量子自旋模型与高度挫折的相互作用。本文采用格位分解波函数分析和大尺度密度矩阵重整化群方法研究了正方晶格上自旋为1的双线性双二次模型，并通过直接或间接的量子跃迁，确定了从著名的反铁磁态到奇异的反铁四极态的量子跃迁。（\pi/2，\pi）$反铁磁态。这许多相虽然不同，但都是向列相。我们还讨论了我们的理论基态相图的理解实验低温相图得到的NMR [P.S. Wang {\it et al.}，物理修订信函117，237001（2016）]和X射线散射[K. Kothapalli等人Nature Communications 7，12728（2016）]测量。我们的研究结果表明，在广泛的铁基材料的超导性有一个共同的起源强关联电子的反铁磁关联。
Since its discovery, iron-based superconductivity has been known to develop near an antiferromagnetic order, but this paradigm fails in the iron chalcogenide FeSe, whose single-layer version holds the record for the highest superconducting transition temperature in the iron-based superconductors. The striking puzzle that FeSe displays nematic order (spontaneously broken lattice rotational symmetry) while being non-magnetic, has led to several competing proposals for its origin in terms of either the $3d$-electron's orbital degrees of freedom or spin physics in the form of frustrated magnetism. Here we argue that the phase diagram of FeSe under pressure could be qualitatively described by a quantum spin model with highly frustrated interactions. We implement both the site-factorized wave-function analysis and the large-scale density matrix renormalization group (DMRG) in cylinders to study the spin-$1$ bilinear-biquadratic model on the square lattice, and identify quantum transitions from the well-known $(\pi,0)$ antiferromagnetic state to an exotic $(\pi,0)$ antiferroquadrupolar order, either directly or through a $(\pi/2,\pi)$ antiferromagnetic state. These many phases, while distinct, are all nematic. We also discuss our theoretical ground-state phase diagram for the understanding of the experimental low-temperature phase diagram obtained by the NMR [P. S. Wang {\it et al.}, Phys. Rev. Lett. 117, 237001 (2016)] and X-ray scattering [K. Kothapalli {\it et al.}, Nature Communications 7, 12728 (2016)] measurements in pressurized FeSe. Our results suggest that superconductivity in a wide range of iron-based materials has a common origin in the antiferromagnetic correlations of strongly correlated electrons.