Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gain and plasmon dynamics in negative-index metamaterials   Photonic metamaterials allow for a range of exciting applications
unattainable with ordinary dielectrics. However, the metallic nature of their
meta-atoms may result in increased optical losses. Gain-enhanced metamaterials
are a potential solution to this problem, but the conception of realistic,
three-dimensional designs is a challenging task. Starting from fundamental
electrodynamic and quantum-mechanical equations we establish and deploy a
rigorous theoretical model for the spatial and temporal interaction of
lightwaves with free and bound electrons inside and around metallic (nano-)
structures and gain media. The derived numerical framework allows us to
self-consistently study the dynamics and impact of the coherent plasmon-gain
interaction, nonlinear saturation, field enhancement, radiative damping and
spatial dispersion. Using numerical pump-probe experiments on a double-fishnet
metamaterial structure with dye molecule inclusions we investigate the build-up
of the inversion profile and the formation of the plasmonic modes in the low-Q
cavity. We find that full loss compensation occurs in a regime where the real
part of the effective refractive index of the metamaterial becomes more
negative compared to the passive case. Our results provide a deep insight into
how internal processes affect the over-all optical properties of active
photonic metamaterials fostering new approaches to the design of practical
loss-compensated plasmonic nanostructures.

17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc