Gap function of hexagonal pnictide superconductor SrPtAs from quasiparticle interference spectrum

Abstract

The pnictide superconductor SrPtAs has a hexagonal layered structure containing inversion symmetry. It is formed by stacking two inequivalent PtAs layers separated by Sr layers. The former have no local (in-plane) inversion symmetry and therefore a (layer-) staggered Rashba spin orbit coupling appears which splits the three Kramers degenerate bands into six quasi-2D bands. The symmetry of the superconducting state of SrPtAs is unknown. Three candidates, spin-singlet $A_{1g}$ and $E_g$ as well as triplet $A_{2u}$ states have been proposed. We predict the quasiparticle interference (QPI) spectrum for these gap functions in t-matrix Born approximation. We show that distinct differences in the pattern of characteristic QPI wave vectors appear. These results may be important to determine the gap symmetry of SrPtAs by STM-QPI method.

5 pages, 4 figures

References in corpus (5)

• Anisotropic Energy Gaps of Iron-based Superconductivity from Intra-band Quasiparticle Interference in LiFeAs
• Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs
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• Model for nodal quasiparticle scattering in a disordered vortex lattice
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