Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the interpretation of manifold ultrafast dynamics in supported
  graphene   Understanding the ultrafast carrier dynamics of graphene on a substrate is a
fundamental step in the development of graphene based opto-electronic devices.
Here, we present ultrafast pump-probe measurements of supported graphene on
quartz for a range of pump fluences that enable us to observe both decreased
and enhanced probe transmission regimes on a femtosecond timescale.
Unexpectedly, at an intermediate pump fluence, an order of magnitude decrease
in the relaxation time constant of the differential transmission is observed.
By employing a number of different models to interpret our experimental data,
we demonstrate the importance of considering both intra- and inter-band
contributions to the dynamical optical conductivity in order to extract a more
physical relaxation time constant of hot optical phonons.

7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas