论文标题
基于Fe的超导体中的多样性异国订单和Fermiology：$ b_ {1g}/b_ {2g} $ fese/（cs，rb）fe $ _2 $ as $ _2 $的统一机制，$ _2 $ an
Diverse Exotic Orders and Fermiology in Fe-based Superconductors: A Unified Mechanism for $B_{1g}/B_{2g}$ Nematicity in FeSe/(Cs,Rb)Fe$_2$As$_2$ and Smectic Order in BaFe$_2$As$_2$
论文作者
论文摘要
在基于Fe的超导体中，各种各样的nematic/enectic Orders在强相关的电子系统中是一个重要的未解决的问题。在过去的十年中，对这些命令的统一理解进行了研究。在本文中，我们解释了$ b_ {1g} $对称性nematic在fese $ _ {1-x} $ te $ _x $，$ b_ {2g} $ symmetry nematicity afe $ _2 $ as $ _2 $ as $ _2 $ as $ _2 $（a = cs，rb）和smect $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 2 $ _2 $ _2。我们通过开发密度波方程来研究自旋波动之间的量子干扰机制。在这种机制中，自然了解了观察到的各种列表/近晶阶的丰富种类。列表/近程顺序取决于每种化合物的费米表面（FS）的特征形状和拓扑。 （i）在fese $ _ {1-x} $ te $ _x $中，每个FS非常小，DXY-轨道孔口袋低于费米水平。在这种情况下，在三个DXZ，DYZ和DXY轨道上的小型自旋波动合作导致$ b_ {1g} $ nematic Order。列表过渡温度$（T_S）$下方的实验性LIFSHITZ过渡是自然复制的。 （ii）在Bafe $ _2 $ AS $ _2 $中，DXY-轨道孔口袋出现在M点附近，并且每个FS相对较大。由于DXY - 轨道筑巢引起的强旋转波动引起$ B_ {1G} $ nematic Order和enectic Order，后者的过渡温度（$ T^*$）超过了前一个$ T_S $。 （iii）在$ _2 $，大型DXY - 轨道孔口袋和四个小零袋中出现的大孔供应$ _2 $中，由于孔掺杂而出现。 $ b_ {2g} $ nematic债券订单由于具有相同的干扰机制而出现在DXY - 轨道孔袋上。目前的Paramagnon干扰机制提供了一个统一的解释，说明了为什么基于Fe的超导体中的各种nematic/enectic Orders是基于FE基基于FE的超导体的良好的费米学，因此如此丰富。
A rich variety of nematic/smectic orders in Fe-based superconductors is an important unsolved problem in strongly correlated electron systems. A unified understanding of these orders has been investigated for the last decade. In this article, we explain the $B_{1g}$ symmetry nematic transition in FeSe$_{1-x}$Te$_x$, the $B_{2g}$ symmetry nematicity in AFe$_2$As$_2$ (A=Cs, Rb), and the smectic state in BaFe$_2$As$_2$ based on the same framework. We investigate the quantum interference mechanism between spin fluctuations by developing the density wave equation. The observed rich variety of nematic/smectic orders is naturally understood in this mechanism. The nematic/smectic orders depend on the characteristic shape and topology of the Fermi surface (FS) of each compound. (i) In FeSe$_{1-x}$Te$_x$, each FS is very small and the dxy-orbital hole pocket is below the Fermi level. In this case, the small spin fluctuations on three dxz, dyz, and dxy orbitals cooperatively lead to the $B_{1g}$ nematic order. The experimental Lifshitz transition below the nematic transition temperature $(T_S)$ is naturally reproduced. (ii) In BaFe$_2$As$_2$, the dxy-orbital hole pocket emerges around M point, and each FS is relatively large. The strong spin fluctuations due to the dxy-orbital nesting give rise to the $B_{1g}$ nematic order and the smectic order, and the latter transition temperature ($T^*$) exceeds the former one $T_S$. (iii) In heavily hole-doped AFe$_2$As$_2$, the large dxy-orbital hole pocket and the four tiny Dirac pockets appear due to the hole-doping. The $B_{2g}$ nematic bond order emerges on the dxy-orbital hole pocket due to the same interference mechanism. The present paramagnon interference mechanism provides a unified explanation of why the variety of nematic/smectic orders in Fe-based superconductors is so rich, based on the well-established fermiology of Fe-based superconductors.
