Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast x-ray diffraction of a ferroelectric soft mode driven by
  broadband terahertz pulses   Intense, few-cycle pulses in the terahertz frequency range have strong
potential for schemes of control over vibrational modes in solid-state
materials in the electronic ground-state. Here we report an experiment using
single cycle terahertz pulses to directly excite lattice vibrations in the
ferroelectric material $\mathrm{Sn_2P_2S_6}$ and ultrafast x-ray diffraction to
quantify the resulting structural dynamics. A model of a damped harmonic
oscillator driven by the transient electric field of the terahertz pulses
describes well the movement of the Sn$^{2+}$ ion along the ferroelectric soft
mode. Finally, we describe an anharmonic extension of this model which predicts
coherent switching of domains at peak THz-frequency fields of 790 kV/cm.

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The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom