论文标题
由非本地库仑相互作用驱动的SN/SI（111）中的拓扑超导性
Topological Superconductivity in Sn/Si(111) driven by non-local Coulomb interactions
论文作者
论文摘要
最近在硼掺杂（$ \ sqrt {3} \ times \ sqrt {3} $）sn/si（111）中观察到了超导性。该材料可以通过三角形晶格上的扩展哈伯德模型描述。在这里，我们使用随机相近似来研究系统的电荷和自旋波动以及系统的超导性能，相对于填充和扩展的相对强度与现场哈驼的相互作用。我们的计算表明，超导式基态差不多半填充和较弱的扩展哈伯德相互作用，表现出手性$ d $ - 波配对。该系统远非半填充，并且对于更强的最近的邻居库仑相互作用，它显示了手性$ p $ - 波（孔掺杂）和$ f $ - 波（电子掺杂）配对。配对对称性对扩展哈伯德相互作用的依赖性表明，电荷波动在库珀对的形成中起着重要作用。最后，计算所有观察到的超导纹理的骑士移位的温度依赖性，并作为一种实验方法提出，以检查超导间隙函数的对称性。
Superconductivity was recently observed in boron-doped ($\sqrt{3}\times\sqrt{3}$)Sn/Si(111). The material can be described by an extended Hubbard model on a triangular lattice. Here, we use the random-phase approximation to investigate the charge and spin fluctuations as well as the superconducting properties of the system with respect to filling and the relative strength of the extended versus the on-site Hubbard interactions. Our calculations reveal that near half-filling and weak extended Hubbard interactions, the superconducting ground state exhibits chiral $d$-wave pairing. Far from half-filling and for stronger nearest-neighbor Coulomb interactions, the system shows chiral $p$-wave (hole-doping) and $f$-wave (electron-doping) pairings. The dependence of the pairing symmetry on the extended Hubbard interactions suggests that charge fluctuations play an important role in the formation of Cooper pairs. Finally, the temperature dependence of the Knight shift is calculated for all observed superconducting textures and put forward as an experimental method to examine the symmetry of the superconducting gap function.
