铁基超导体中不同有序的起源：AFe $_2$ As $_2$（A=Cs，Rb）中45 $^\circ$旋转向列性
Origin of diverse nematic orders in Fe-based superconductors: 45$^\circ$ rotated nematicity in AFe$_2$As$_2$ (A=Cs, Rb)
摘要：
铁基超导体中各种向列性及其序参量的起源问题越来越受到人们的关注。最近，在重空穴掺杂（$n_d=5.5$）化合物AFe $_2$ As $_2$（A=Cs，Rb）中发现了一种新的有序结构.所发现的向列性具有$B_{2g}$（= $d_{xy}$）对称性，在含有$n_d\approx6$的常见化合物中，从$B_{1g}$（= $d_{x^2-y^2}$）向列性旋转$45^\circ$。我们预测，“氢键键序”，这是相关跳跃的破坏，是负责$B_{2g}$在AFe $_2$作为$_2$的氢键键序。AFe $_2$中的狄拉克口袋作为$_2$是稳定$B_{2g}$键级所必需的。A $_{1-x}$ Ba $_x$ Fe $_2$ As $_2$中的$B_{1g}$和$B_{2g}$向列性都是由描述自旋涨落驱动的电荷不稳定性的Aslamazov-Larkin多体过程自然诱导的。本研究为通过改变费米面的轨道性质和拓扑结构来控制电荷向列性的性质提供了重要的启示。
英文摘要：
The origin of diverse nematicity and their order parameters in Fe-based superconductors have been attracting increasing attention. Recently, a new type of nematic order has been discovered in heavily hole-doped ($n_d=5.5$) compound AFe$_2$As$_2$ (A=Cs, Rb). The discovered nematicity has $B_{2g}$ (=$d_{xy}$) symmetry, rotated by $45^\circ$ from the $B_{1g}$ (=$d_{x^2-y^2}$) nematicity in usual compounds with $n_d\approx6$. We predict that the "nematic bond order", which is the symmetry-breaking of the correlated hopping, is responsible for the $B_{2g}$ nematic order in AFe$_2$As$_2$. The Dirac pockets in AFe$_2$As$_2$ is essential to stabilize the $B_{2g}$ bond order. Both $B_{1g}$ and $B_{2g}$ nematicity in A$_{1-x}$Ba$_x$Fe$_2$As$_2$ are naturally induced by the Aslamazov-Larkin many-body process, which describes the spin-fluctuation-driven charge instability. The present study gives a great hint to control the nature of charge nematicity by modifying the orbital character and the topology of the Fermi surface.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
