Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: CaTe: a new topological node-line and Dirac semimetal   Topological semimetals recently stimulate intense research activities.
Combining first-principles calculations and effective model analysis, we
predict that CaTe is topological node-line semimetal when spin-orbit coupling
(SOC) is ignored. We also obtain the nearly flat surface state which has the
drumhead characteristic. When SOC is included, three node lines evolve into a
pair of Dirac points along the $M-R$ line. These Dirac points are robust and
protected by $C_{4}$ rotation symmetry. Once this crystal symmetry is broken,
the Dirac points will be eliminated, and the system becomes a strong
topological insulator.

17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph