Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear level attraction of cavity axion polariton in
  antiferromagnetic topological insulator   Strong coupling between cavity photons and various excitations in condensed
matters boosts the field of light-matter interaction and generates several
exciting sub-fields, such as cavity optomechanics and cavity magnon polariton.
Axion quasiparticles, emerging in topological insulators, were predicted to
strongly couple with the light and generate the so-called axion polariton.
Here, we demonstrate that there arises a gapless level attraction in cavity
axion polariton of antiferromagnetic topological insulators, which originates
from a nonlinear interaction between axion and the odd-order resonance of
cavity. Such a novel level attraction is essentially different from
conventional level attractions with the mechanism of either a linear coupling
or a dissipation-mediated interaction, and also different from the level
repulsion induced by the strong coupling in common polaritons. Our results
reveal a new mechanism of level attractions, and open up new roads for
exploring the axion polariton with cavity technologies. They have potential
applications for quantum information and dark matter research.

3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess