Characterization of graphene through anisotropy of constant-energy maps in angle-resolved photoemission

Abstract

We show theoretically how constant-energy maps of the angle-resolved photoemission intensity can be used to test wave function symmetry in graphene. For monolayer graphene, we demonstrate that the observed anisotropy of ARPES spectra is a manifestation of what has been recently branded as electronic chirality. For bilayer graphene, we show that the anisotropy of the constant-energy maps may be used to extract information about the magnitude and sign of interlayer coupling parameters and about symmetry breaking inflicted on a bilayer by the underlying substrate.

Tuning the charge carriers in epitaxial graphene on SiC(0001) from electron to hole via molecular doping with C60F48

“…We note that within the ARPES data, we only see one branch of the Dirac cone along C À K due to the interplay between p-polarised radiation and the pseudo-spin properties of the two sublattices in graphene for this particular measurement geometry. [16][17][18][19] This manifests itself in each MDC as a single peak at E F , rather than two symmetrically disposed about K, and the relative position of the peak with respect to the K point yields the carrier polarity. Figure 1 clearly shows the transition from an n-type to p-type doped graphene layer.…”

A First-Principles Time-Dependent Density Functional Theory Framework for Spin and Time-Resolved Angular-Resolved Photoelectron Spectroscopy in Periodic Systems

“…This is a characteristic feature of ARPES on graphene which has been observed in many experiments 53 and that is due to the chiral character of Dirac states at the K point. 54 In this work we do not include any dissipation channel. The finite line-width observed in ARPES is thus a direct consequence of the finite time window of the probe pulse.…”

Tuning the electronic structure of monolayer graphene/MoS2van der Waals heterostructures via interlayer twist

“…Figures 2a-2b are acquired from the Gr overlayer with a twist angle of 19° with respect to the MoS 2 bottomlayer. The anisotropy of the spectral intensity in the CEM as well as in the ARPES bandmap is due to the photoemission selection rules [35]. From the data in Fig.…”