Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tunable circular dipolelike system in graphene: Mixed electron-hole
  states   Coupled electron-hole states are realized in a system consisting of a
combination of an electrostatic potential barrier and ring-shaped potential
well, which resembles a circular dipole. A perpendicular magnetic field induces
confined states inside the Landau gaps which are mainly located at the barrier
or ring. Hybridizations between the barrier and ring states are seen as
anticrossings in the energy spectrum. As a consequence, the energy levels show
an oscillating dependence on the electrostatic potential strength in
combination with an oscillating migration of the wave functions between the
barrier and ring. At the anticrossing points the quantum state consists of a
mixture of electron and hole. The present system mimics closely the behavior of
a relativistic dipole on gapped graphene.

24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
7
The categories of this paper are: hep-th