Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic and Geometric Corrugation of Periodically Rippled,
  Self-nanostructured Graphene Epitaxially Grown on Ru(0001)   Graphene epitaxially grown on Ru(0001) displays a remarkably ordered pattern
of hills and valleys in Scanning Tunneling Microscopy (STM) images. To which
extent the observed "ripples" are structural or electronic in origin have been
much disputed recently. A combination of ultrahigh resolution STM images and
Helium Atom diffraction data shows that i) the graphene lattice is rotated with
respect to the lattice of Ru and ii) the structural corrugation as determined
from He diffraction is substantially smaller (0.015 nm) than predicted (0.15
nm) or reported from X-Ray Diffraction or Low Energy Electron Diffraction. The
electronic corrugation, on the contrary, is strong enough to invert the
contrast between hills and valleys above +2.6 V as new, spatially localized
electronic states enter the energy window of the STM. The large electronic
corrugation results in a nanostructured periodic landscape of electron and
holes pockets.

36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
1
The categories of this paper are: cs
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an