Orbital driven two-dome superconducting phases in multiorbital superconductors

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...
Ausführliche Beschreibung

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 α β and the next-nearest-neighbor 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. Ausführliche Beschreibung