Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Harvesting and storing laser energy with graphene-cu compound structure   Graphene-metal compound structure has been reported as a novel and
outstanding component used in electrical and optical devices. We report on a
first-principles study of graphene-cu compound structure, showing its capacity
of converting laser energy into electrical power and storing the harvested
energy for a long time. A real-time and real-space time-dependent density
functional method (TDDFT) is applied for the simulation of electrons dynamics
and energy absorption. The laser-induced charge transfer from copper layer to
graphene layer is observed and represented by plane-averaged electron
difference and dipoles. The effects of laser frequency on the excitation energy
and charge transfer are studied as well. The enhancement of C-C {\sigma}-bond
and decreasing of electron density corresponding to {\pi}-bond within graphene
layer indicate the way in which the transferred-charges are stored. In
addition, the shift and oscillations of dipole along z-direction after the
application of laser pulse offer a concept that the compound structure has the
ability of storing the harvested energy for a long time.

11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin