Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electromagnetic Scattering by Spheres of Topological Insulators   The electromagnetic scattering properties of topological insulator (TI)
spheres are systematically studied in this paper. Unconventional backward
scattering caused by the topological magneto-electric (TME) effect of TIs are
found in both Rayleigh and Mie scattering regimes. This enhanced backward
scattering can be achieved by introducing an impedance-matched background which
can suppress the bulk scattering. For the cross-polarized scattering
coefficients, interesting antiresonances are found in the Mie scattering
regime, wherein the cross-polarized electromagnetic fields induced by the TME
effect are trapped inside TI spheres. In the Rayleigh limit, the quantized TME
effect of TIs can be determined by measuring the electric-field components of
scattered waves in the far field.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
19
The categories of this paper are: eess
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org