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The polarization dependence of hyper-Rayleigh second harmonic light scattering (SHS) and hyper-Raman light scattering (HRS) measured for liquid CDCl3 show the effect of long-range correlation of molecular orientation and vibration. HRS from the ν1, ν4, and ν5 vibration modes is polarized transverse to the scattering wavevector, whereas HRS from the ν2, ν3, and ν6 vibration modes and SHS from the ν0 orientation mode all show longitudinal polarization. The transverse polarized HRS is accounted for by long range vibration correlation due to dipole–dipole interaction for molecules at 20–400 nm separation. Longitudinal SHS and HRS are due to the combined effect of long range dipole–dipole orientation correlation and the increment in the molecular first hyperpolarizability induced by short range intermolecular interactions.
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This content will become publicly available on April 28, 2026
Super diffusive length dependent thermal conductivity in one-dimensional materials with structural defects: Longitudinal to transverse phonon scattering leads to κ ∝ L 1/3 law
Structural defects in one-dimensional heat conductors couple longitudinal (stretching) and transverse (bending) vibrations. This coupling results in the scattering of longitudinal phonons to transverse phonons and backward. We show that the decay rate of longitudinal phonons due to this scattering scales with their frequencies as ω3/2 within the long wavelength limit (ω → 0), which is a more efficient scattering compared to the traditionally considered Rayleigh scattering within the longitudinal band (ω2). This scattering results in temperature-independent thermal conductivity, depending on the size as κ ∝ L1/3 for sufficiently long materials. This predicted length dependence is observed in nanowires, although the temperature dependence seen there is possibly because of deviations from pure one-dimensional behavior. The significant effect of interaction of longitudinal phonons with transverse phonons is consistent with the earlier observations of a substantial suppression of thermal energy transport by kinks, obviously leading to such interaction, although anharmonic interaction can also be significant.
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- Award ID(s):
- 2201027
- PAR ID:
- 10611618
- Publisher / Repository:
- AIP
- Date Published:
- Journal Name:
- The Journal of Chemical Physics
- Volume:
- 162
- Issue:
- 16
- ISSN:
- 0021-9606
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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