Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Near-complete violation of Kirchhoff s law in thermal radiation in
  ultrathin magnetic Weyl semimetal films   The ability to break Kirchhoff s law is of fundamental importance in thermal
radiation. Various nonreciprocal emitters have been proposed to break the
balance between absorption and emission. However, the thicknesses of the
nonreciprocal materials are usually larger than 1/10 times of the wavelength.
Besides, the previous proposed nonreciprocal emitters are complex, thus they
can hardly be fabricated in experiment to verify the Kirchhoff s law for
nonreciprocal materials. In this paper, we investigate the nonreciprocal
thermal radiation of the magnetic Weyl semimetal (MWSM) film atop of the metal
substrate. It is found that the strong nonreciprocal radiation at the
wavelength of 9.15 {\mu}m can be achieved when the thickness of the MWSM film
is 100 nm. The enhanced nonreciprocity is attributed to the Fabry-Perot
resonances. The results indicate that the MWSM film is the promising candidate
to engineer the ultrathin and simple nonreciprocal thermal emitters. What is
perhaps most intriguing here is that the proposed structure can be more easily
fabricated in experiment to verify the Kirchhoff s law for nonreciprocal
materials.

35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
2
The categories of this paper are: math