| These spontaneous fluctuations are driven by collective acoustic vibrational modes, known as phonons, in the gigahertz frequency range. |
| Any phonons going with the flow will be reflected by this invisible frontier and return the way they came until they hit the original event horizon, which will likewise reflect them. |
| However, the interaction of photons and phonons in micro structures is a subject that draws more and more attention from researchers. |
| A laser beam incident on the sample surface interacts with the sample phonons, causing photon emission at a lower wavelength by Raman scattering. |
| Phenomena such as resonant tunneling, radiative transition, and interactions between electrons, photons, and phonons are being investigated and utilized for THz QCL design and optimization. |
| This important spectral region contains material information related to phonons, excitons, and Cooper pairs. |
