Orbital driven two-dome superconducting phases in multiorbital superconductors

Jing Liu; Qing-Wei Wang; Liang-Jian Zou

doi:10.1016/j.physleta.2020.127118

paper

Orbital driven two-dome superconducting phases in multiorbital superconductors

arXiv:2104.12957 · doi:10.1016/j.physleta.2020.127118

Abstract

We theoretically study the superconductivity in multiorbital superconductors based on a three-orbital tight-banding model. With appropriate values of the nearest-neighbour exchange $J_{1}^{α β}$ and the next-nearest-neighbour exchange $J_{2}^{α β}$ , 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.

16 pages, 6 figures