Higher angular momentum pairing states in Sr2RuO4 in the presence of longer-range interactions

The superconducting symmetry of Sr2RuO4 remains a puzzle. Time-reversal symmetry breaking dx2−y2+igxy(x2−y2) pairing has been proposed for reconciling multiple key experiments. However, its stability remains unclear. In this work, we theoretically study the superconducting instabilities in Sr2RuO4, including the effects of spin-orbit coupling (SOC), in the presence of both local and longer-range interactions within a random-phase approximation. We show that the inclusion of second-nearest-neighbor repulsions, together with nonlocal SOC in the B2g channel or orbital-anisotropy of the nonlocal interactions, can have a significant impact on the stability of both dx2−y2- and g-wave pairing channels. We analyze the properties, such as Knight shift and spontaneous edge current, of the realized dx2−y2+ig, s′+idxy, and mixed helical pairings in different parameter spaces, and we find that the dx2−y2+ig solution is in better agreement with the experimental data.