DAMPING OF OPTICAL PHONONS IN GA1-XALXAS ALLOYS

被引：8

作者：

JUSSERAND, B ^{[1
]}

MOLLOT, F ^{[1
]}

QUAGLIANO, LG ^{[1
]}

LEROUX, G ^{[1
]}

PLANEL, R ^{[1
]}

机构：

[1] CNR,IST METODOL AVANZATE INORGAN,AREA RIC,ROME,ITALY

来源：

PHYSICAL REVIEW LETTERS | 1991年 / 67卷 / 20期

关键词：

D O I：

10.1103/PhysRevLett.67.2803

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We measure for the first time the average mechanical response of a III-V mixed crystal with a two-mode behavior, Ga1-xAlxAs, to a vibrational excitation at frequencies in the gap between the two optical-phonon branches. These frequencies are selected by the boundary conditions applied to the optical phonons confined in the GaAs layers of GaAs/Ga1-xAlxAs superlattices. We measure their variations with the composition of the alloy layer. The alloy lattice dynamics predicted in the coherent potential approximation is perfectly verified: The gap is shown to be divided into GaAs- and AlAs-type ranges. At the cutoff frequency the average damping becomes infinite.

引用

页码：2803 / 2806

页数：4

共 12 条

[1] SPECTROSCOPIC INVESTIGATION OF THE ELECTRONIC STATES IN NARROW COUPLED GAAS ALAS QUANTUM WELLS WITH INDIRECT BAND-STRUCTURE [J].