Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transport and quantum coherence in graphene rings: Aharonov-Bohm
  oscillations, Klein tunneling and particle localization   Simulating quantum transport through mesoscopic, ring-shaped graphene
structures, we address various quantum coherence and interference phenomena.
First, a perpendicular magnetic field, penetrating the graphene ring, gives
rise to Aharonov-Bohm oscillations in the conductance as a function of the
magnetic flux, on top of the universal conductance fluctuations. At very high
fluxes the interference gets suppressed and quantum Hall edge channels develop.
Second, applying an electrostatic potential to one of the ring arms, $nn'n$- or
$npn$-junctions can be realized with particle transmission due to normal
tunneling or Klein tunneling. In the latter case the Aharonov-Bohm oscillations
weaken for smooth barriers. Third, if potential disorder comes in to play, both
Aharonov-Bohm and Klein tunneling effects rate down, up to the point where
particle localization sets in.

37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg