Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Versatile Setup for Ultrafast Broadband Optical Spectroscopy of
  Coherent Collective Modes in Strongly Correlated Quantum Systems   A femtosecond pump-probe setup is described that is optimised for broadband
transient reflectivity experiments on solid samples over a wide range of
temperatures. By combining a temporal resolution of 45 fs and a broad detection
range between 1.75 and 2.85 eV, this apparatus can provide insightful
information on the interplay between coherent collective modes and high-energy
electronic excitations, which is one of the distinctive characteristics of
strongly interacting and correlated quantum systems. The use of a single-shot
readout CMOS array detector at frame rates up to 10 kHz allows to resolve
coherent oscillations with amplitudes below 10$^{-4}$ in $\Delta$R/R. We
demonstrate the operation of this setup on the prototypical charge-transfer
insulator La$_2$CuO$_4$, revealing the presence of coherent optical phonons
with frequencies as high as 13 THz.

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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
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The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
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The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin