Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Amphoteric refraction at the interface between isotropic and anisotropic
  media   It is found that the amphoteric refraction, i.e. the refraction can be either
positive or negative depending on the incident angles, could occur at a planar
interface associated with a uniaxially anisotropic positive index media (PIM)
or an anisotropic negative index media (NIM). Particularly, the anomalous
negative refraction can occur at a planar interface from an isotropic PIM to an
anisotropic PIM, whereas the anomalous positive refraction occurs at the
interface from an isotropic PIM to an anisotropic NIM. The optimal conditions
to yield the two unusual refractions are obtained. The difference of the two
types of amphoteric refraction is discussed.

20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph