Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Emission and amplification of surface plasmons in resonant - tunneling
  van der Waals heterostructures   We predict a new mechanism of surface plasmon amplification in
graphene-insulator-graphene van der Waals heterostructures. The amplification
occurs upon the stimulated interlayer electron tunneling accompanied by the
emission of a coherent plasmon. The quantum-mechanical calculations of the
non-local high-frequency tunnel conductivity show that a relative smallness of
the tunneling exponent can be compensated by a strong resonance due to the
enhanced tunneling between electron states with collinear momenta in the
neighboring graphene layers. With the optimal selection of the barrier layer,
the surface plasmon gain due to the inelastic tunneling can compensate or even
exceed the loss due to both Drude and interband absorption. The tunneling
emission of the surface plasmons is robust against a slight twist of the
graphene layers and might explain the electroluminescence from the
tunnel-coupled graphene layers observed in the recent experiments.

3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat