Effects of gold cluster intercalation in graphene: stationary waves and modified QPI features
arXiv:2607.28297
The paper investigates how gold atoms intercalated beneath epitaxial graphene on SiC create cluster-induced scattering that generates distinctive standing-wave patterns and modified quasiparticle‑interference features near the graphene M points, using a T‑matrix model to match FT‑STS observations and compute energy‑dependent LDOS contrasts.
Abstract
Gold intercalation beneath epitaxial graphene on SiC produces a cluster phase with unusual standing waves and quasiparticle-interference (QPI) features concentrated near the graphene M points. We show that this can be explained by Au intercalation below graphene hollow sites, which induces a local scattering potential on the six surrounding carbon atoms. Within a T-matrix treatment, this ring-like scatterer produces elliptical QPI structures centered near M, in agreement with the experimental FT-STS measurements. We further show that these QPI features naturally generate the nearly stationary standing-wave patterns observed in real space. Finally, we compute the local-density-of-states contrast on and off a small cluster and show that its sign and magnitude are strongly energy dependent, consistent with the experimental observations.
9 pages, 6 figures