Abstract

It is shown that interlayer electron tunneling in the quasi-two-dimensional ensemble of Hubbard fermions leads to the realization of the gapless superconducting phase with the chiral (d + id)-wave order parameter symmetry, not for a single value of sodium ion concentration, but in a wide range of concentrations. Precisely this situation corresponds to experimental data on the layered sodium cobaltite intercalated by water (Na_xCoO₂ ⋅ yH₂O). Intra-atomic electron repulsion that determines the strong electron correlation regime leads to the representation of Hubbard fermions, the interaction of which ensures Cooper instability. Intersite intralayer interactions between fermions considerably affect the positions of nodal points of the chiral order parameter and change the critical concentration at which a topological transition occurs in the 2D system of Hubbard fermions.

中文翻译：

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具有三角形格子的强相关层状材料中的无间隙手性超导（d + id）-波相

摘要

结果表明，在哈伯德费米子的准二维整体中的层间电子隧穿导致以手性（d + id）-波序参数对称而不是对于钠离子浓度的单个值实现无间隙超导相的实现。，但浓度范围很广。正是这种情况对应于实验数据由水嵌入层状钠的钴酸（钠_X的CoO ₂ ⋅ ÿ ħ ₂O）。原子内的电子排斥力决定了强的电子相关机制，导致了哈伯德费米子的出现，而后者的相互作用确保了库珀的不稳定性。费米子之间的站点间层内相互作用极大地影响了手性有序参数的结点位置，并改变了哈伯德费米子二维系统中发生拓扑转变的临界浓度。