Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of chiral photocurrent transport in the quantum Hall regime
  in graphene   Optical excitation provides a powerful tool to investigate non-equilibrium
physics in quantum Hall systems. Moreover, the length scale associated with
photo-excited charge carries lies between that of local probes and global
transport measurements. Here, we investigate non-equilibrium physics of
optically-excited charge carriers in graphene through photocurrent measurements
in the integer quantum Hall regime. We observe that the photocurrent oscillates
as a function of Fermi level, revealing the Landau-level quantization, and that
the photocurrent oscillations are different for Fermi levels near and distant
from the Dirac point. Our observation qualitatively agrees with a model that
assumes the photocurrent is dominated by chiral edge transport of
non-equilibrium carriers. Our experimental results are consistent with electron
and hole chiralities being the same when the Fermi level is distant from the
Dirac point, and opposite when near the Dirac point.

20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph