Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of electronic structure of periodically strained
  graphene   We induced periodic biaxial tensile strain in polycrystalline graphene by
wrapping it over a substrate with repeating pillar-like structures with a
periodicity of 600 nm. Using Raman spectroscopy, we determined to have
introduced biaxial strains in graphene in the range of 0.4% to 0.7%. Its band
structure was characterized using photoemission from valance bands, shifts in
the secondary electron emission, and x-ray absorption from the carbon 1s levels
to the unoccupied graphene conduction bands. It was observed that relative to
unstrained graphene, strained graphene had a higher work function and higher
density of states in the valence and conduction bands. We measured the
conductivity of the strained and unstrained graphene in response to a gate
voltage and correlated the changes in their behavior to the changes in the
electronic structure. From these sets of data, we propose a simple band diagram
representing graphene with periodic biaxial strain.

6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin