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    "headline": "The Pulse Arrived Before the Molecule Could Turn",
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    "dek": "A single-cycle terahertz field let researchers read electric responses from dissolved dyes at room temperature before rotational motion took over.",
    "summary": "A single-cycle terahertz field let researchers read electric responses from dissolved dyes at room temperature before rotational motion took over.",
    "body_text": "Researchers report room-temperature Stark spectroscopy in water using intense, single-cycle terahertz pulses. Because the field changes on a sub-picosecond timescale, the experiment probes solvated molecules before they can substantially rotate in the liquid. Measurements on Malachite Green and Methyl Orange showed distinct linear and quadratic spectral responses, which the authors connect respectively to permanent-dipole and polarizability effects using time-dependent density-functional calculations. The preprint establishes a technique in two dye systems; it does not demonstrate universal molecular identification, biological effects or a commercial sensor.",
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    "tags": [
      "terahertz",
      "Stark spectroscopy",
      "water",
      "molecular physics"
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      "title": "arXiv preprint 2608.04662",
      "publisher": "arXiv",
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    "title": "The Pulse Arrived Before the Molecule Could Turn",
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