High-resolution coherent Raman spectroscopy of vibrons in solid parahydrogen

Coherent Raman spectroscopy is carried out for the Q₁(0) vibron of solid parahydrogen crystal with a spectral resolution better than 1 MHz. The Raman spectrum is measured for the temperature from 4.2 to 13 K under constant molecular density condition. We show that the temperature dependence of the Raman spectrum should be quantitatively described via the interaction between vibrons and thermal acoustic phonons through a two-phonon scattering process. We also investigate the effect of molecular density on the Raman shift and obtain the hopping interaction strength for the vibron band.