Optical Phonon Dephasing Channels in GaN revealed by the Coherent Phonon Method

In this paper, we report on dephasing channels of the Al(LO) and the high-frequency E2 mode of a wurtzite structure GaN. The temperature dependence of dephasing rates reveals the anharmonic channels for each mode, and the photo-excited carrier density dependence compares the coherent phonon dephasing through the electron-phonon coupling between the Al(LO) and the E2 mode.