Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Encapsulation Narrows Excitonic Homogeneous Linewidth of Exfoliated
  MoSe$_2$ Monolayer   The excitonic homogeneous linewidth of an exfoliated monolayer MoSe$_2$
encapsulated in hexagonal boron nitride is directly measured using
multidimensional coherent spectroscopy with micron spatial resolution. The
linewidth is 0.26 $\pm$ 0.02 meV, corresponding to a dephasing time $T_2
\approx$ 2.5 ps, which is almost half the narrowest reported values for
non-encapsulated MoSe$_2$ flakes. We attribute the narrowed linewidth to
Coulomb screening by the encapsulated material and suppression of non-radiative
processes. Through direct measurements of encapsulated and non-encapsulated
monolayers, we confirm that encapsulation reduces the sample inhomogeneity.
However, linewidths measured using photoluminescence and linear absorption
remain dominated by inhomogeneity, and these linewidths are roughly 5 times
larger than the homogeneous linewidth in even the highest-quality encapsulated
materials. The homogeneous linewidth of non-encapsulated monolayers is very
sensitive to temperature cycling, whereas encapsulated samples are not modified
by temperature cycling. The nonlinear signal intensity of non-encapsulated
monolayers is degraded by high-power optical excitation, whereas encapsulated
samples are very resilient to optical excitation with optical powers up to the
point of completely bleaching the exciton.

13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess