Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Classification of Collective Modes in a Charge Density Wave by
  Momentum-Dependent Modulation of the Electronic Band Structure   We present time- and angle-resolved photoemission spectroscopy measurements
on the charge density wave system CeTe$_{3}$. Optical excitation transiently
populates the unoccupied band structure and reveals a gap size of 2$\Delta$ =
0.59 eV. The occupied Te-5p band dispersion is coherently modified by three
modes at $\Omega_{1}$ = 2.2 THz, $\Omega_{2}$ = 2.7 THz and $\Omega_{3}$ = 3
THz. All three modes lead to small rigid energy shifts whereas $\Delta$ is only
affected by $\Omega_{1}$ and $\Omega_{2}$. Their spatial polarization is
analyzed by fits of a transient model dispersion and DFT frozen phonon
calculations. We conclude that the modes $\Omega_{1}$ and $\Omega_{2}$ result
from in-plane ionic lattice motions, which modulate the charge order, and that
$\Omega_{3}$ originates from a generic out-of-plane $A_{1g}$ phonon. We thereby
demonstrate how the rich information from trARPES allows identification of
collective modes and their spatial polarization, which explains the
mode-dependent coupling to charge order.

33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas