论文标题
删除债券长度和轨道对称性在控制$ t_c $ in yba $ _2 $ _2 $ cu $ _3 $ o $ _7 $中的作用
Disentangling the role of bond lengths and orbital symmetries in controlling $T_c$ in YBa$_2$Cu$_3$O$_7$
论文作者
论文摘要
最佳掺杂YBCO（YBA $ _ {2} $ CU $ _ {3} $ o $ $ _ {7} $）的临界温度很高，在92 K处。很大程度上相信，库珀对YBCO和其他丘陵形式的形式和其他丘陵形式是由于旋转的波动，问题和详细的机构远不是固定的。在目前的工作中，我们采用了最先进的\ emph {ab intio}能够计算最佳掺杂YBCO中的低能和高能自旋波动。我们对最新的非弹性中子散射和共振非弹性X射线散射测量值进行基准测试。此外，我们使用应变作为外部参数来调节自旋波动和超导性。我们通过施加理想的菌株以及具有完全宽松的结构的菌株来解散钡 - 阳极氧杂交，层间耦合和轨道对称性的作用。我们表明，缩短Cu层之间的距离有利于增强的费米表面嵌套，从而增加了旋转波动并驱动$ T_ {C} $。但是，当结构完全放松时，电子流向d $ _ {z^2} $轨道，这是由于缩短的BA-O键，这对超导性有害
Optimally doped YBCO (YBa$_{2}$Cu$_{3}$O$_{7}$) has a high critical temperature, at 92 K. It is largely believed that Cooper pairs form in YBCO and other cuprates because of spin fluctuations, the issue and the detailed mechanism is far from settled. In the present work, we employ a state-of-the-art \emph{ab initio} ability to compute both the low and high energy spin fluctuations in optimally doped YBCO. We benchmark our results against recent inelastic neutron scattering and resonant inelastic X-ray scattering measurements. Further, we use strain as an external parameter to modulate the spin fluctuations and superconductivity. We disentangle the roles of Barium-apical Oxygen hybridization, the interlayer coupling and orbital symmetries by applying an idealized strain, and also a strain with a fully relaxed structure. We show that shortening the distance between Cu layers is conducive for enhanced Fermi surface nesting, that increases spin fluctuations and drives up $T_{c}$. However, when the structure is fully relaxed electrons flow to the d$_{z^2}$ orbital as a consequence of a shortened Ba-O bond which is detrimental for superconductivity
