Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric-Field-Induced Antiferromagnetic Insulating State in a Metallic
  Ferromagnet   We show that a static electric field induces the transition from a
ferromagnetic metal to an antiferromagnetic insulator owing to the Bloch
oscillation of conduction electrons. In the steady state, the electric current
is inversely proportional to the applied electric field, implying the
nonperturbative insulating nature that is different from the Wannier-Stark
localization. Possible experimental realization based on recent terahertz pulse
sources is discussed.

15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
18
The categories of this paper are: econ