Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Omnidirectional field enhancements drive giant nonlinearities in
  epsilon-near-zero waveguides   Bulk materials possessing a relative electric permittivity $\varepsilon$
close to zero exhibit giant Kerr nonlinearities. However, harnessing this
response in guided-wave geometries is not straightforward, due to the extreme
and counter-intuitive properties of epsilon-near-zero materials. Here we
investigate, through rigorous calculations of the Kerr nonlinear coefficient,
how the remarkable nonlinear properties of such materials can be exploited in
several different types of structures, including bulk films, plasmonic
nanowires, and metal nanoapertures. We find the largest Kerr nonlinear response
when both the modal area and the group velocity are simultaneously minimized,
corresponding to omnidirectional field enhancement. The physical insights
developed will be key for understanding and engineering nonlinear nanophotonic
systems with extreme nonlinearities and point to new design paradigms.

26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol