Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tamm states and nonlinear surface modes in photonic crystals   We predict the existence of surface gap modes, known as Tamm states for
electronic systems, in truncated photonic crystals formed by two types of
dielectric rods. We investigate the energy threshold, dispersion, and modal
symmetries of the surface modes, and also demonstrate the existence and
tunability of nonlinear Tamm states in binary photonic crystals with nonlinear
response.

11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg