Quasiparticle interference testing the possible pairing symmetry in Sr2RuO4*

The quasiparticle interference (QPI) patterns of the superconducting state in Sr 2 RuO 4 are theoretically studied by taking into account the spin–orbital coupling and two different pairing modes, chiral p-wave pairing and equal d-wave pairing, in order to propose an experimental method to test them. Both of the QPI spectra for the two pairing modes have clearly peaks evolving with energy, and their locations can be determined from the tips of the constant energy contour. But the number, location, and evolution of these peaks with energy are different between the two pairing modes. The different behaviors of the QPI patterns in these two pairing modes may help to resolve whether Sr 2 RuO 4 is a chiral p-wave or d-wave superconductor.