论文标题
扭曲双层铜氧化物中的高温拓扑超导性
High-temperature topological superconductivity in twisted double layer copper oxides
论文作者
论文摘要
当将二维材料（例如石墨烯或过渡金属二分法）组装成双层时，各种层之间的二维材料（例如石墨烯或过渡金属二分法）时，就会发生各种各样的新现象。作为此范式的新应用，我们考虑了由两个单层$ d $ - 具有扭曲角度$θ$的结构组成的结构，可以通过机械去角质剥落van der waals-bonded高$ t_c $ t_c $ copper氧化物材料来实现，例如bi $ _2 $ _2 $ _2 $ _2 $ __2 $ __2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ o。根据对称参数和详细的微观建模，我们预测，对于$ 45^{\ rm o} $附近的一系列扭曲角度，此类双层均形成了一个可靠的，完全散发的拓扑阶段，具有自发损坏的时间交流对称性和保护的chiral ralaana Edge Modes。当$θ\大约45^{\ rm时 o} $，拓扑阶段在接近$ t_c \ simeq 90 $ k的温度下设置，从而提供了长期寻求真正的高温拓扑超导体的认识。
A great variety of novel phenomena occur when two-dimensional materials, such as graphene or transition metal dichalcogenides, are assembled into bilayers with a twist between individual layers. As a new application of this paradigm, we consider structures composed of two monolayer-thin $d$-wave superconductors with a twist angle $θ$ that can be realized by mechanically exfoliating van der Waals-bonded high-$T_c$ copper oxide materials, such as Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$. On the basis of symmetry arguments and detailed microscopic modelling, we predict that for a range of twist angles in the vicinity of $45^{\rm o}$, such bilayers form a robust, fully gapped topological phase with spontaneously broken time-reversal symmetry and protected chiral Majorana edge modes. When $θ\approx 45^{\rm o}$, the topological phase sets in at temperatures close to the bulk $T_c\simeq 90$ K, thus furnishing a long sought realization of a true high-temperature topological superconductor.
