Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three-Dimensional Quantum Anomalous Hall Effect in Ferromagnetic
  Insulators   The quantum anomalous Hall effect (QAHE) hosts the dissipationless chiral
edge states associated with the nonzero Chern number, providing potentially
significant applications in future spintronics. The QAHE usually occurs in a
two-dimensional (2D) system with time-reversal symmetry breaking. In this work,
we propose that the QAHE can exist in three-dimensional (3D) ferromagnetic
insulators. By imposing inversion symmetry, we develop the topological
constraints dictating the appearance of 3D QAHE based on the parity analysis at
the time-reversal invariant points in reciprocal space. Moreover, using
first-principles calculations, we identify that 3D QAHE can be realized in a
family of intrinsic ferromagnetic insulating oxides, including layered and
non-layered compounds that share a centrosymmetric structure with space group
$R\bar{3}m$ (No. 166). The Hall conductivity is quantized to be
$-\frac{3e^2}{hc}$ with the lattice constant $c$ along $c$-axis. The chiral
surface sheet states are clearly visible and uniquely distributed on the
surfaces that are parallel to the magnetic moment. Our findings open a
promising pathway to realize the QAHE in 3D ferromagnetic insulators.

19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys