Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Graphene on metal surface: gap opening and n-doping   Graphene grown on metal surface, Cu(111), with a boron nitride(BN) buffer
layer is studied for the first time. Our first-principles calculations reveal
that charge is transferred from the copper substrate to graphene through the BN
buffer layer which results in a n-doped graphene in the absence of a gate
voltage. More importantly, a gap of 0.2 eV which is comparable to that of a
typical narrow gap semicondutor opens just 0.5 eV below the Fermi-level at the
Dirac point. The Fermi-level can be easily shifted inside this gap to make
graphene a semiconductor which is crucial for graphene-based electronic
devices. A graphene based p-n junction can be realized with graphene eptaxially
grown on metal surface.

7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol