This commit is contained in:
2025-06-30 17:32:17 +08:00
parent cb5e588d8c
commit 4b8eb1c50c

View File

@@ -8,18 +8,18 @@
我们将这 21 个声子模式分为两类18 个极性可以忽略的声子模式(即极性为零或非常弱的声子),在拉曼散射过程中它们的电极性造成的效应可以忽略;
3 个强极性声子模式,在拉曼光谱中电极性效应是可观测的。
Phonons involved in different Raman incidence configurations (normal, grazing, and edge incidence)
are located at different positions in reciprocal space,
all of which are near the #sym.Gamma point,
with the distance from the #sym.Gamma point determined by the wavelength of the incident light,
and the relative position to the #sym.Gamma point determined by the direction of incidence.
For each such position around the #sym.Gamma point,
there are 21 phonon modes (degenerate modes are counted according to their multiplicity).
We classify these 21 phonon modes into two categories:
18 negligible-polar phonons (i.e., phonons with zero or very weak electrical polarity),
for which the effect of polarity can be ignored in the Raman scattering process;
and the other three strong-polar phonons,
where the polarity gives rise to observable effects in the Raman spectra.
Phonons involved in Raman scattering under different incidence configurations (normal, grazing, and edge incidence)
are located at distinct positions in reciprocal space,
all close to the #sym.Gamma point.
The distance from the #sym.Gamma point is determined by the wavelength of the incident light,
and the direction from the #sym.Gamma point is determined by the incidence configurations.
At each such position near the #sym.Gamma point,
there exist 21 phonon modes (with degeneracies counted accordingly).
These modes can be categorized into two groups:
18 negligible-polar phonons (i.e., zero or very weak electrical polarity),
whose electrical polarity can be disregarded in the Raman scattering process;
and three strong-polar phonons,
whose electrical polarity leads to observable effects in the Raman spectra.
这个分类是有意义的。从微观上讲,它也和原子的振动方向有关。