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SUMMARY:Nonlinear terahertz spectroscopy on liquid water
DTSTART;VALUE=DATE-TIME:20220707T124500Z
DTEND;VALUE=DATE-TIME:20220707T133000Z
DTSTAMP;VALUE=DATE-TIME:20260521T040718Z
UID:indico-contribution-743@events.ncbj.gov.pl
DESCRIPTION:Speakers: F. Novelli (Department of Physical Chemistry II\, Ru
 hr University Bochum\, 44780 Bochum\, DE)\nWater is one of the most studie
 d and least understood liquids[1]. While several anomalies in the thermody
 namic\, macroscopic properties of water are well documented[2]\, on the mi
 croscopic scale this special liquid is characterized by a dynamic\, tetrah
 edral network of hydrogen bonded (HB) molecules rearranging on the picosec
 ond timescale[3]. Thus\, terahertz (THz) spectroscopy is uniquely suited t
 o probe the dynamics of the HB water network. \n\nThe first results detail
 ing the nonlinear response of water in the THz frequency range are recent\
 , and the molecular interpretation is a matter of ongoing discussion. Tcyp
 kin et al.[4\,5]\, Ghalgaoui et al.[6]\, and Novelli et al.[7–10] all fo
 und that the third-order nonlinear response of water in the THz range has 
 a similar magnitude\, but proposed different explanations. The transient r
 esponse of liquid water was assigned to cascaded second-order anharmonicit
 y of the intramolecular O–H stretching modes[4]\; to the field-induced i
 rreversible ionization of water molecules[6]\; or to the resonant excitati
 on of molecular reorientations[8]. \n\nWe performed a series of non-linear
  experiments at ~1 and 12.3 THz on liquid water at user facilities[7–10]
 . By comparing results obtained on a static sample and a free-flowing wate
 r jet at 12.3 THz\, we were able to disentangle the distinct contributions
  by thermal\, acoustic\, and nonlinear optical effects[9]. Recently\, we s
 howed that the non-linear response of water at ~1 THz depends weakly on th
 e temperature of the bulk liquid[10]. Based on these observations\, we sug
 gest that the THz fields could be reorienting the hydrogen-bonded water mo
 lecules in the liquid phase\, as originally proposed in ref.[8]. \n\n[1]	P
 . Ball\, Nature. 452 (2008) 291–292. \n[2]	P. Gallo\,et al. Pettersson\,
  Water: A Tale of Two Liquids\, Chem. Rev. 116 (2016) 7463–7500. \n[3]	F
 . Novelli\, B. Guchhait\, M. Havenith\, Materials (Basel). 13 (2020) 1311.
 \n[4]	A. Tcypkin\,et al.\, Phys. Rev. Appl. 15 (2021) 054009.\n[5]	A.N. Tc
 ypkin\, et al.\, Opt. Express. 27 (2019) 10419. \n[6]	A. Ghalgaoui\, et al
 .\, J. Phys. Chem. Lett. 11 (2020) 7717–7722.\n[7]	F. Novelli\, et al.\,
  Appl. Sci. 10 (2020) 5290. \n[8]	F. Novelli\, et al.\, J. Phys. Chem. B. 
 124 (2020) 4989–5001. \n[9]	F. Novelli\, et al.\, Phys. Chem. Chem. Phys
 . 24 (2022) 653–665. \n[10]	F. Novelli\, et al.\, Temperature-independen
 t non-linear terahertz transmission by liquid water\, (2022).  https://doi
 .org/10.48550/arxiv.2206.03998.\n\nhttps://events.ncbj.gov.pl/event/75/con
 tributions/743/
LOCATION:Novotel Warszawa Centrum Róża
URL:https://events.ncbj.gov.pl/event/75/contributions/743/
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