Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: In-plane orientation effects on the electronic structure, stability and
  Raman scattering of monolayer graphene on Ir(111)   We employ angle-resolved photoemission spectroscopy (ARPES) to investigate
the electronic structures of two rotational variants of epitaxial, single-layer
graphene on Ir(111). As grown, the more-abundant R0 variant is nearly
charge-neutral, with strong hybridization between graphene and Ir bands near
the Fermi level. The graphene Fermi surface and its replicas exactly coincide
with Van Hove singularities in the Ir Fermi surface. Sublattice symmetry
breaking introduces a small gap-inducing potential at the Dirac crossing, which
is revealed by n-doping the graphene using K atoms. The energy gaps between
main and replica bands (originating from the moir\'e interference pattern
between graphene and Ir lattices) is shown to be non-uniform along the mini-
zone boundary due to hybridization with Ir bands. An electronically mediated
interaction is proposed to account for the stability of the R0 variant. The
variant rotated 30{\deg} in-plane, R30, is p-doped as grown and K doping
reveals no band gap at the Dirac crossing. No replica bands are found in ARPES
measurements. Raman spectra from the R30 variant exhibit the characteristic
phonon modes of graphene, while R0 spectra are featureless. These results show
that the film/substrate interaction changes from chemisorption (R0) to
physisorption (R30) with in-plane orientation. Finally, graphene-covered Ir has
a work function lower than the clean substrate but higher than graphite.

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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol