Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Charge and spin transport in edge channels of a $\nu=0$ quantum Hall
  system on the surface of topological insulators   Three-dimensional topological insulators of finite thickness can show the
quantum Hall effect (QHE) at the filling factor $\nu=0$ under an external
magnetic field if there is a finite potential difference between the top and
bottom surfaces. We calculate energy spectra of surface Weyl fermions in the
$\nu=0$ QHE and find that gapped edge states with helical spin structure are
formed from Weyl fermions on the side surfaces under certain conditions. These
edge channels account for the nonlocal charge transport in the $\nu=0$ QHE
which is observed in a recent experiment on (Bi$_{1-x}$Sb$_x$)$_2$Te$_3$ films.
The edge channels also support spin transport due to the spin-momentum locking.
We propose an experimental setup to observe various spintronics functions such
as spin transport and spin conversion.

25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex