Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast terahertz probes of interacting dark excitons in
  chirality-specific semiconducting single-walled carbon nanotubes   Ultrafast terahertz spectroscopy accesses the {\em dark} excitonic ground
state in resonantly-excited (6,5) SWNTs via internal, direct dipole-allowed
transitions between lowest lying dark-bright pair state $\sim$6 meV. An
analytical model reproduces the response which enables quantitative analysis of
transient densities of dark excitons and {\em e-h} plasma, oscillator strength,
transition energy renormalization and dynamics. %excitation-induced
renormalization. Non-equilibrium, yet stable, quasi-1D quantum states with dark
excitonic correlations rapidly emerge even with increasing off-resonance
photoexcitation and experience a unique crossover to complex phase-space
filling of %a complex distribution between both dark and bright pair states,
different from dense 2D/3D excitons influenced by the thermalization, cooling
and ionization to free carriers.

36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph