Detecting nonunitary multiorbital superconductivity with Dirac points at finite energies

Abstract

Determining the symmetry of the order parameter of unconventional superconductors remains a recurrent topic and nontrivial task in the field of strongly correlated electron systems. Here we show that the behavior of Dirac points away from the Fermi energy is a potential tool to unveil the orbital structure of a superconducting state. In particular, we show that gap openings in such Dirac crossings are a signature of nonunitary multiorbital superconducting order. Consequently, also spectral features at higher energy can help us to identify broken symmetries of superconducting phases and the orbital structure of nonunitary states. Our results show how angle-resolved photoemission spectroscopy measurements can be used to detect nonunitary multiorbital superconductivity.