We theoretically study the superconductivity in multiorbital superconductors based on a three-orbital tight-banding model. With appropriate values of the nearest-neighbor exchange $J_1^{\alpha \beta }$ and the next-nearest-neighbor exchange $J_2^{\alpha \beta }$, we find a two-dome structure in the $T_c-n$ phase diagram: one dome in the doping range $n<3.9$ where the superconducting (SC) state is mainly $s_{x^2{y}^2}$ component contributed by inter-orbital pairing, the other dome in the doping range $3.9<n<4.46$ where the SC state is mainly $s_{x^2{y}^2}+s_{x^2+y^2}$ components contributed by intra-orbital pairing. We find that the competition between different orbital pairing leads to two-dome SC phase diagrams in multiorbital superconductors, and different matrix elements of $J_1$ and $J_2$ considerably affect the boundary of two SC domes.

我们从理论上研究了基于三轨道紧密带模型的多轨道超导体的超导性。具有最近邻居交换的适当值${Ĵ}_{\mathrm{1个}}^{\alpha \beta }$ 和下一个最近邻居交换 ${Ĵ}_2^{\alpha \beta }$，我们在 ${Ť}_C-ñ$ 相图：掺杂范围内的一个圆顶 $ñ<3.9$ 超导（SC）状态主要是 $s_{X^2{ÿ}^2}$ 组分由轨道间配对贡献，掺杂范围内的另一个圆顶 $3.9<ñ<4.46$ SC状态主要是 $s_{X^2{ÿ}^2}+s_{X^2+{ÿ}^2}$成分由轨道内配对贡献。我们发现，不同轨道配对之间的竞争导致了多轨道超导体中的两球SC相图，以及不同的矩阵元素。${Ĵ}_{\mathrm{1个}}$ 和 ${Ĵ}_2$ 大大影响了两个SC圆顶的边界。