Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetotransport of Dirac Fermions on the surface of a topological
  insulator   We study the properties of Dirac fermions on the surface of a topological
insulator in the presence of crossed electric and magnetic fields. We provide
an exact solution to this problem and demonstrate that, in contrast to their
counterparts in graphene, these Dirac fermions allow relative tuning of the
orbital and Zeeman effects of an applied magnetic field by a crossed electric
field along the surface. We also elaborate and extend our earlier results on
normal metal-magnetic film-normal metal (NMN) and normal metal-barrier-magnetic
film (NBM) junctions of topological insulators [Phys. Rev. Lett. {\bf 104},
046403 (2010)]. For NMN junctions, we show that for Dirac fermions with Fermi
velocity $v_F$, the transport can be controlled using the exchange field
${\mathcal J}$ of a ferromagnetic film over a region of width $d$. The
conductance of such a junction changes from oscillatory to a monotonically
decreasing function of $d$ beyond a critical ${\mathcal J}$ which leads to the
possible realization of magnetic switches using these junctions. For NBM
junctions with a potential barrier of width $d$ and potential $V_0$, we find
that beyond a critical ${\mathcal J}$, the criteria of conductance maxima
changes from $\chi= e V_0 d/\hbar v_F = n \pi$ to $\chi= (n+1/2)\pi$ for
integer $n$. Finally, we compute the subgap tunneling conductance of a normal
metal-magnetic film-superconductor (NMS) junctions on the surface of a
topological insulator and show that the position of the peaks of the zero-bias
tunneling conductance can be tuned using the magnetization of the ferromagnetic
film. We point out that these phenomena have no analogs in either conventional
two-dimensional materials or Dirac electrons in graphene and suggest
experiments to test our theory.

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The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph