Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-loss forward and backward surface plasmons in a semiconductor
  nanowire coated by helical graphene strips   In the long-wavelength approximation, the effective conductivity tensor is
introduced for graphene ribbons (strips) placed periodically at the interface
between two media. The resulting conducting surface is considered as a coating
for semiconductor nanowire. For the hybrid waves of such nanowire the
dispersion equations are obtained in explicit form. Two types of surface
plasmons are found to exist: (i) the modified surface plasmons, which originate
from the ordinary surface plasmons of a graphene-coated semiconductor nanowire,
and (ii) the spoof plasmons, which arise on the array of graphene ribbons and
may possess forward-wave and backward-wave dispersion. It is revealed that the
spoof surface plasmons are low-loss ones, and their frequencies,
field-confinement and group velocities can be tuned widely by adjusting the
coil angle and width of helical graphene strips.

32
The categories of this paper are: atom-ph
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
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th