Canonico M, Poweleit C, Menéndez J, Debernardi A, Johnson S R, Zhang Y-H
Department of Physics and Astronomy, Arizona State University, Box 871504, Tempe, Arizona 85287-1504, USA.
Phys Rev Lett. 2002 May 27;88(21):215502. doi: 10.1103/PhysRevLett.88.215502. Epub 2002 May 14.
The temperature dependence of the frequencies and linewidths of the Raman-active longitudinal optical (LO) phonons in GaAs and AlAs have been measured. The low-temperature lifetime of the LO phonon in AlAs is found to be 9.7 ps, very close to the corresponding GaAs value of 9.5 ps. This contradicts early theoretical predictions. The agreement between theory and experiment can be restored when the accidental degeneracy between the AlAs LO phonon frequency and a feature in the two-phonon density of states is taken into account.
已测量了砷化镓（GaAs）和砷化铝（AlAs）中拉曼活性纵向光学（LO）声子的频率和线宽与温度的关系。发现砷化铝中LO声子的低温寿命为9.7皮秒，与砷化镓相应的9.5皮秒的值非常接近。这与早期的理论预测相矛盾。当考虑到砷化铝LO声子频率与双声子态密度中的一个特征之间的偶然简并时，理论与实验之间的一致性可以恢复。
