Probing the pairing symmetry in kagome superconductors based on the single-particle spectrum

Abstract: We investigate the single-particle spectra of recently discovered kagome superconductors. We examine nine distinct superconducting pairing symmetries, including the uniform $s$-wave pairing function, nearest-neighbor and next-nearest-neighbor $s$-wave pairing, $p+ip$ pairing, $d+id$ pairing, and $f$-wave pairing states. These pairing states can be classified into irreducible representations of the $C_{6v}$ point group. Our findings suggest that these pairing states can be differentiated by analyzing the energy bands, spectral function, and local density of states. Additionally, we explore the single impurity effect, which could potentially assist in further distinguishing these pairing symmetries.