The effect of ion irradiation on dephasing of coherent optical phonons in GaP

Abstract

The dephasing of coherent longitudinal optical (LO) phonons in ion-irradiated GaP has been investigated with a femtosecond pump-probe technique based on electro-optic sampling. The dephasing time of the coherent LO phonon is found to be dramatically prolonged by the introduction of a small amount of defects by means of Ga-ion irradiation. The maximum dephasing time observed at room temperature is 9.1 ps at a Ga${}^{+}$ ion dose of 10${}^{13}$/cm${}^2$, which is significantly longer than the value of 8.3 ps for GaP before ion irradiation. The longer dephasing time is explained in terms of the suppression of electron-LO-phonon scattering by the presence of defect-induced deep levels.

6 pages, 7 figures

References in corpus (2)

• Ultrafast Structure Switching through Nonlinear Phononics
• Giant nonlinear optical effects induced by nitrogen-vacancy centers in diamond crystals