Fig. 1: Pseudospin winding in graphene and QPI patterns with and without backscattering.

a Pseudospin winding (black arrows) in a single Dirac cone. b Pseudospin winding and spin-orbit split bands of graphene in the presence of SOC. Blue and red arrows illustrate the tilted pseudospin winding. The blue (red) Dirac cone corresponds to spin up (down) configuration. c, d The geometrical constructions of the phase overlap of electron scattering at a constant energy. The cross section of incoming \(\overrightarrow{k}\) and scattered \({\overrightarrow{k}}^{{\prime} }\) states are marked by filled red areas, where (c) depicts backscattering. To model the suppression of backscattering, we include angle-dependent scattering of the form \({\cos }^{2}(\theta /2)\). e The scattering electron phase overlap as a function of scattering momentum \(q=|\overrightarrow{k}-{\overrightarrow{k}}^{{\prime} }|\) if backscattering is allowed (blue curve) or forbidden (black curve). The absence of any scattering at momenta beyond 2k is an artefact of this approximate geometric construction. f Phenomenological QPI power spectrum without and g with backscattering.