Due to the strong interaction between the optical phonons and plasma waves, the optical reststrahlen frequency is raised while the plasma frequency is lowered. The acoustic phonons can have gain under application of a suitable drift field. The form of the attenuation constant suggests that the ...
We report the results of the investigation of the acoustic and optical phonons in quasi-two-dimensional antiferromagnetic semiconductors of the transition metal phosphorus trisulfide family with Mn, Fe, Co, Ni, and Cd as metal atoms. The Brillouin-Mandelstam and Raman light scattering spectroscopies ...
optical–phonon relaxation time scale is much shorter than the time scale corresponding to acoustic phonons and may be evidence of a more general mechanism in TNSMs. Our results provide first insights into electron cooling process for the nodal-line bulk state via energy exchange with the lattice...
For Raman spectroscopic study, the temperature-dependent shift in phonon energy has been frequently modelled by considering the decay of optical phonons into acoustic phonons with the same frequency but opposite momenta20,48,54. In this model, the temperature-dependent phonon energy can be expressed ...
Analysis of the temperature evolution of phonon modes allowed us to identify special points in the dynamics of the PNN crystal lattice at T1 = 280 K and Tm = 150 K. It is shown that anomalies in the temperature behavior of optical phonons in the vicinity of T1 can be associated with the...
(2) optical phonon decay to acoustic phonons; (3) acoustic phonon propagation to the far-field region in the material (thermal conduction). Correspondingly, in a non-quantized system with continuous electronic DOS, possible blocking mechanisms can be introduced in each relaxation stage to prolong ...
level structure; however, various complications can arise from the vibronic character owing to, for example, nuclear-wave-function overlap (Franck–Condon and Huang–Rhys effects), symmetry breaking (Jahn–Teller effects) and interaction with other phonons in the diamond lattice (Debye–Waller effects...
Patel and K. D. Patel Since the interatomic distance in a crystal is not isotropic but rather varies with the crystallographic direction, one would expect this directional variation to affect the banding of states. Thus, although the energy gap, which characterizes a semiconductor, has the same ...
Within a single valley, carriers will undergo momentum relaxation due to scattering with acoustic phonons, however, quantifying these effects would require knowledge of material-specific scattering rates. Any intermediate state following momentum relaxation is subject to the same Pauli blockade as the ...
Here, the authors investigate the Raman spectra of few-layered WS2when the excitation energy is in resonance with the dark exciton, and observe a Fano resonance between dark excitonsand zone-edge acoustic phonons. Qing-Hai Tan ,Yun-Mei Li ...