From 8b0611979afe889e5cb61d7a95065ccc52e982af Mon Sep 17 00:00:00 2001
From: chn <chn@chn.moe>
Date: Fri, 4 Jul 2025 11:02:38 +0800
Subject: [PATCH]

---
 paper/ref.bib                              | 24 +++++++++++++++++
 paper/result/perfect/non-polar/default.typ | 30 +++++++++++-----------
 paper/todo.typ                             | 18 ++++++++++++-
 3 files changed, 56 insertions(+), 16 deletions(-)

diff --git a/paper/ref.bib b/paper/ref.bib
index 62ddf5f..5a8836d 100644
--- a/paper/ref.bib
+++ b/paper/ref.bib
@@ -683,3 +683,27 @@ CNKICite: 6},
 	pages = {205202},
 	file = {PDF:/home/chn/Zotero/storage/5U5BPLCX/Gerstmann et al. - 2003 - Formation and annealing of nitrogen-related complexes in SiC.pdf:application/pdf},
 }
+
+@article{_n-sic_2008,
+	title = {n-{SiC的电子拉曼散射及二级拉曼谱研究}},
+	issn = {1000-3290},
+	url = {https://kns.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFQ&dbname=CJFD2008&filename=WLXB200805091},
+	abstract = {研究了利用离子注入法得到的掺氮n-SiC拉曼光谱.理论线形分析表明,与4H-SiC相比,6H-SiC中LO声子等离子体激元耦合模(LOPC模)拉曼位移随自由载流子浓度变化较小.514.5nm激发光下得到的电子拉曼散射光谱表明,k位处由1s(A1)到1s(E)的能谷轨道跃迁带来的拉曼谱6H-SiC中有四条,4H-SiC中有二条;高频630.3及635cm-1处观察到的谱线被认为与深能级缺陷有关.最后,利用纤锌矿型结构二级拉曼散射选择定则指认了6H-及4H-SiC二级拉曼谱.},
+	language = {zh-CN},
+	number = {5},
+	urldate = {2025-07-04},
+	journal = {物理学报},
+	author = {{韩茹} and {杨银堂} and {柴常春}},
+	year = {2008},
+	note = {foundation: 国家部委预研资助项目(批准号:51308030201)资助的课题{\textasciitilde}{\textasciitilde}；
+download: 403
+album: 基础科学
+CLC: O472
+dbcode: CJFQ
+dbname: CJFD2008
+filename: WLXB200805091
+CNKICite: 6},
+	keywords = {倍频谱, 电子拉曼散射, 碳化硅, 轨道能谷分裂},
+	pages = {3182--3187},
+	file = {n-SiC的电子拉曼散射及二级拉曼谱研究:/home/chn/Zotero/storage/2PYQG2SP/n-SiC的电子拉曼散射及二级拉曼谱研究.pdf:application/pdf},
+}
diff --git a/paper/result/perfect/non-polar/default.typ b/paper/result/perfect/non-polar/default.typ
index 1b15baa..cfde06e 100644
--- a/paper/result/perfect/non-polar/default.typ
+++ b/paper/result/perfect/non-polar/default.typ
@@ -1,24 +1,24 @@
 === Phonons with Negligible Polarities
 
-我们用 gamma 点的声子来近似弱极性的声子。
+用 gamma 点的声子来近似。
 
-Gamma 点的声子被用于
+Gamma 点的声子被用于近似参与拉曼散射的弱极性声子，无论入射配置。
+这个近似是因为这些声子的色散曲线在 Gamma 点附近连续且非常接近 Gamma 点，并且已经被广泛使用。
 
-// We investigate phonons at Gamma instead of the exact location near Gamma.
-Phonons at the #sym.Gamma point were used
-  to approximate negligible-polar phonons that participating in Raman processes
+Phonons at the #sym.Gamma point were used to approximate negligible-polar phonons,
   regardless of the wavevector of the incident and scattered light.
-This approximation is widely adopted (cite) and justified by the fact that,
-  although the phonons participating in Raman processes are not these strictly located at the #sym.Gamma point,
-  they are very close to the #sym.Gamma point in reciprocal space
-    (about 0.01 nm#super[-1] in back-scattering configurations with 532 nm laser light,
-    which corresponds to only 1% of the smallest reciprocal lattice vector of 4H-SiC,
-    see orange dotted line in @figure-discont),
-  and their dispersion at #sym.Gamma point is continuous with vanishing derivatives.
-Therefore, negligible-polar phonons involved in Raman processes
-    have nearly indistinguishable properties from those at the #sym.Gamma point.
+This approximation is based on the fact that
+    the dispersion of these phonons is continuous and very close to the #sym.Gamma point,
+  and has been widely adopted in the literature @_n-sic_2008.
 
-gamma 点处 18 个声子的表示。它们的拉曼张量的形状可以确定，但大小无法确定。
+18 个声子属于 12 个表示。拉曼张量的形状可以确定，大小不能。
+
+这些声子的拉曼张量的形状可以通过对称性分析来确定。
+Gamma 点声子满足 C#sub[6v] 点群对称性，18 个模式包含了 2A#sub[1] + 4B#sub[1] + 2E#sub[1] + 4E#sub[2] 共 12 个表示；
+  其中简并表示（E1 和 E2）的拉曼张量的形状可以通过进一步考虑在 C#sub[2v] 点群中的表示来确定，如表所示。
+其中，B#sub[1] 模式具有零拉曼张量，不参与拉曼散射；
+  其它表示的模式具有非零拉曼张量分量，可能可以在适当的偏振配置下在拉曼实验中观察到。
+然而，模式是否足够强以在实验中可见取决于其拉曼张量分量的大小，而仅通过对称性分析无法确定这些大小。
 
 // Representation of these 18 phonons, and the shape of their Raman tensors could be determined in advance.)
 Phonons at the #sym.Gamma point satisfy the C#sub[6v] point group symmetry,
diff --git a/paper/todo.typ b/paper/todo.typ
index b0625b6..2f283fe 100644
--- a/paper/todo.typ
+++ b/paper/todo.typ
@@ -43,7 +43,23 @@
           - [x] 中文
           - [x] 英文
           - [x] 调整语言
-      - [ ] 弱极性
+      - [/] 弱极性
+        - [x] Gamma 近似
+          - [x] 中文
+          - [x] 英文
+          - [ ] 调整语言
+        - [ ] 表示
+          - [ ] 中文
+          - [ ] 英文
+          - [ ] 调整语言
+        - [ ] 估算拉曼张量
+          - [ ] 中文
+          - [ ] 英文
+          - [ ] 调整语言
+        - [ ] 第一性原理计算
+          - [ ] 中文
+          - [ ] 英文
+          - [ ] 调整语言
   - [ ] 杂项
     - [ ] N#sub[C]C#sub[Si] 有什么好处？
     - [ ] 是否有其它需要研究的点缺陷？