Figure 1

ARPES intensity constant energy maps. Upper line: $\mathrm{gr}/\mathrm{Ir}(111)$; lower line: $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$. (a)–(c) and (f)–(h) Mini-Brillouin zone around the $K$ point. (d),(i) Schematic representations of the principal Dirac cone with its replicas. The red hexagon represents the mini-Brillouin zone generated by the moiré superpotential. (e),(j) Moiré scheme of the stacking areas of gr rings centered on hcp, fcc, and atop substrate sites. The colors display the enhancement of the potential difference between the faulted and unfaulted half of the moiré unit cell by the Ir cluster superlattice.Reuse & Permissions

Figure 2

(a) ARPES intensity of the $\pi$ band of graphene in $\mathrm{gr}/\mathrm{Ir}(111)$, around the $K$ point, along the $p\Gamma K$ and the $\Gamma K$ directions. A linear dispersion is observed along both directions. (b) ARPES intensity of the $\pi$ band of graphene in $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$ along the same two directions. In (a) and (b) the dots represent the result of the MDCs fitting. (c) The fitted band positions. Red and black squares were determined by fitting the MDCs extracted from (a) and (b). The $k$-vector error bars are determined as the HWHM of the Lorentzian fits of the MDCs and are representative of the spread of the band intensity. Error bars in energy (20 meV) are not displayed. The blue curves represent the band dispersion predicted by the TB3 model, whereas black lines are the linear fits of the experimental band for the $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$. In $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$ the profile is highly asymmetric compared to TB3 and $\mathrm{gr}/\mathrm{Ir}(111)$.Reuse & Permissions

Figure 3

(a),(b) ARPES intensity of the graphene $\pi$ band along the $p\Gamma K$ direction in $\mathrm{gr}/\mathrm{Ir}(111)$ (a) and $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$ (b). (c),(d) Corresponding energy distribution curve plots. (e) $C\mathrm{\text{−}}1s$ core levels for an Ir coverage of $\theta =0.15\pm 0.05\mathrm{ML}$. Inset: Zoom on the $C\mathrm{\text{−}}1s$ peak showing a shift of $30\pm 30\mathrm{meV}$ after the cluster growth. (Normal emission, photon energy 450 eV.) (f) Energy distribution spectra from $\mathrm{gr}/\mathrm{Ir}(111)$ and $\mathrm{Ir}/\mathrm{gr}/\mathrm{Ir}(111)$ measured at the $M$ point of the second Brillouin zone. Inset: The top of the $\sigma$ band shifts by $30\pm 30\mathrm{meV}$ after the cluster growth.Reuse & Permissions