Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quenching of Intervalley Exchange Coupling in the Presence of
  Momentum-Dark States in TMDCs   Monolayers of transition metal dichalcogenides are promising materials for
valleytronic applications, since they possess two individually addressable
excitonic transitions at the non-equivalent $K$ and $K'$ points with different
spins, selectively excitable with light of opposite circular polarization.
Here, it is of crucial importance to understand the elementary processes
determining the lifetime of these optically injected valley excitons. In this
study, we perform microscopic calculations based on a Heisenberg equation of
motion formalism to investigate the efficiency of the intervalley coupling in
the presence (W based TMDCs) and absence (Mo based TMDCs) of energetically low
lying momentum-dark exciton states. While we predict a valley exciton lifetime
on the order of some hundreds of fs in the absence of low lying momentum-dark
states we demonstrate a strong quenching of the valley lifetime in the presence
of such states.

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The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: eess
12
The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas