Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Colossal magnetoresistance in a nonsymmorphic antiferromagnetic
  insulator   Here we investigate antiferromagnetic Eu$_{5}$In$_{2}$Sb$_{6}$, a
nonsymmorphic Zintl phase. Our electrical transport data show that
Eu$_{5}$In$_{2}$Sb$_{6}$ is remarkably insulating and exhibits an exceptionally
large negative magnetoresistance, which is consistent with the presence of
magnetic polarons. From {\it ab initio} calculations, the paramagnetic state of
Eu$_{5}$In$_{2}$Sb$_{6}$ is a topologically nontrivial semimetal within the
generalized gradient approximation (GGA), whereas an insulating state with
trivial topological indices is obtained using a modified Becke-Johnson
potential. Notably, GGA+U calculations suggest that the antiferromagnetic phase
of Eu$_{5}$In$_{2}$Sb$_{6}$ may host an axion insulating state. Our results
provide important feedback for theories of topological classification and
highlight the potential of realizing clean magnetic narrow-gap semiconductors
in Zintl materials.

31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg