test-typst/section/perfect/non-polar/default.typ

@@ -10,7 +10,7 @@ This approximation is widely adopted (cite) and justified by the fact that,
     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 frequencies and vibration amplitudes from those at the #sym.Gamma point.
+    have nearly indistinguishable properties from those at the #sym.Gamma point.
 
 #include "figure-discont.typ"
 
@@ -85,3 +85,5 @@ Besides, there are small peeks at xxx,
 #include "table-nopol.typ"
 
 #include "figure-raman.typ"
+
+// TODO: 解释为什么 E1 可以看到

test-typst/section/perfect/polar/default.typ

@@ -8,28 +8,36 @@
 // 若考虑到到入射光不是严格沿着 z 方向，而是有一个小的角度（例如 10 度），则此时有一个声子模式沿着 x 方向，另外两个声子模式则为 y-z 两个方向的混合。
 // (没有在图上表示)
 
-Strong-polar phonons heavily depend on the direction of their wavevectors
-  due to long-range Coulomb interactions between atoms in semiconductors.
-This causes the strong-polar phonon modes corresponding to different incident light directions
-  having different frequencies (i.e., discontinuity of colored lines near #sym.Gamma point in @figure-discont),
-  and their vibration directions also vary accordingly.
-For incident laser propagating along the z direction,
-  the relevant phonon modes are those along the A-#sym.Gamma line and symmetry of C#sub[6v] point group applies,
-  leading to two modes (two peeks in Raman spectra),
+Strong-polar phonon modes caused by different incident light directions are different,
+  due to long-range Coulomb interactions between atoms in semiconductors,
+  showing discontinuity in the scattering spectra near the #sym.Gamma point (see @figure-discont).
+For incident light propagating along the z direction (phonon modes on the A-#sym.Gamma line),
+  symmetry of C#sub[6v] point group applies and leading to two modes (two peeks in Raman spectra),
   including an E#sub[1] mode (pink line in @figure-discont, vibration in-plane)
     and an A#sub[1] mode (green line in @figure-discont, vibration along z-direction).
-When the light is incident along the y direction,
-  the relevant phonon modes are those along the #{sym.Gamma}-K line and only symmetry of C#sub[2v] applies.
-The mode vibration in z direction (A#sub[1] mode in C#sub[2v])
-  will have much lower frequency (green line in @figure-discont),
-  and the E#sub[1] mode C#sub[6v] will degenerate into two modes in C#sub[2v],
-  including B#sub[2] mode (blue line in @figure-discont, vibration along x direction)
-    and B#sub[1] mode (red line in @figure-discont, vibration in y direction).
-When the light is incident along random directions,
-  no symmetry applies, and there will be three phonon modes.
+When the light is incident along other directions, symmetry in plane was broken and C#sub[6v] symmetry no longer holds,
+  and there will be three phonon modes in theory.
+For example, when the light is incident along the y direction (phonon modes on the #{sym.Gamma}-K line),
+  symmetry of C#sub[2v] applies and three modes exist in dispersion curves,
+  including an A#sub[1] mode (green line in @figure-discont, vibration along z direction),
+  a B#sub[2] mode (blue line in @figure-discont, vibration along x direction),
+  and a B#sub[1] mode (red line in @figure-discont, vibration in y direction).
+When the light is incident along a direction between z and y,
+  three phonon modes will exist, but vibration in the mixed direction.
+
+// 有许多沿 z 方向入射的 4H-SiC 拉曼实验，它们都观察到了两个峰。
+// 但没有人在实验上观察到沿其它方向入射的三个峰。
+// 在我们的实验中，我们发现第三个峰只有在聚焦到样品内部时才会出现。
+// 根据它在不同偏振下的可见性和距离 E2 主峰的距离，我们认定它就是我们要找的峰。
+
+// 极性声子对入射方向非常敏感。拉曼光谱中位置相近的峰实际上是不同的振动方向。我们预言，当入射光斜时，LO 峰会向高频移动，并且会出现三个峰。
+// 实验验证了我们的猜想。如图，LO 峰如何如何。
+// 此外，这个 TO 峰可以通过聚焦到内部来得到。
+// 我们还注意到，TO 峰会因为偏振方向的不同而发生一些偏移。这可以由双折射解释。
+
+
+
 
 // 极性声子模式还会与载流子发生较强的相互作用。
 
-@figure-discont
-
 #include "table-pol.typ"