diff --git a/paper/result/perfect/default.typ b/paper/result/perfect/default.typ index cf9f625..526a097 100644 --- a/paper/result/perfect/default.typ +++ b/paper/result/perfect/default.typ @@ -1,9 +1,27 @@ == Phonons in Perfect 4H-SiC -总共有 21 个声子模式。我们把它分成 18 个极性很小的和 3 个极性很强的两类。 +不同方向入射光的声子位置不同。 + +声子的性质与它们在倒空间中的位置(即波矢)有关,而参与拉曼散射的声子波矢则由激光波长和拉曼入射配置(正入射、掠入射、边入射)决定。 +在我们的实验(绿光)中,参与拉曼散射的声子都位于 Gamma 点附近(距离仅 xxx 埃),而与 Gamma 点的相对方向则根据入射配置而定。 +对于正入射,声子大致位于 Gamma-A 线上;对于边入射,声子大致位于 Gamma-K 线上。对于掠入射,声子不位于任何高对称线上。 + +Properties of phonons depend on their positions in reciprocal space (i.e., wavevectors), + and the wavevectors of phonons participating in a Raman scattering process + are determined by the Raman experiment configuration. +In our experiments (back-scattering with 532 nm laser light), + phonons involved in Raman scattering are all located near the #sym.Gamma point + (about $5.13 times 10^(-3) angstrom$ from the #sym.Gamma point), + and their relative directions from the #sym.Gamma point depend on the incidence configurations. +For normal and edge incidence, + phonons participating in Raman process are approximately located along the #sym.Gamma–A and #sym.Gamma–K lines, + respectively, as illustrated in @figure-discont. +For grazing incidence, phonons are not located on any high-symmetry lines, and not shown in the figure. + +#include "figure-discont.typ" + +每个点都有 21 个声子模式。我们把它分成 18 个极性很小的和 3 个极性很强的两类。 -对应于不同拉曼入射配置(正入射、掠入射、边入射)的声子位于倒空间中的不同位置。 -它们都位于 Gamma 点附近,与 Gamma 点的距离由入射光波长决定,而与 Gamma 点的相对位置则由入射方向决定。 对于每一个 Gamma 附近的点,都有 21 个声子模式(简并模式按简并数计)。 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; 和 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。 @@ -24,6 +42,12 @@ These modes can be categorized into two groups: 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。 这个分类基于这样的事实: + 在 4H-SiC 的原胞中,四个 Si 原子携带类似的正的 Born 有效电荷(BEC), + 而四个 C 原子携带类似的负的 BEC(见 @table-bec)。 +在 18 个弱极性声子中, + 两个 Si 原子的振动方向大致与另外两个 Si 原子相反, + C 原子也是如此, + 导致宏观极性的抵消。 This classification is based on the fact that the four Si atoms in the primitive cell of 4H-SiC carry similar positive Born effective charges (BECs), diff --git a/paper/result/perfect/non-polar/figure-discont.typ b/paper/result/perfect/figure-discont.typ similarity index 100% rename from paper/result/perfect/non-polar/figure-discont.typ rename to paper/result/perfect/figure-discont.typ diff --git a/paper/result/perfect/non-polar/default.typ b/paper/result/perfect/non-polar/default.typ index f092cb3..25475d2 100644 --- a/paper/result/perfect/non-polar/default.typ +++ b/paper/result/perfect/non-polar/default.typ @@ -16,8 +16,6 @@ This approximation is widely adopted (cite) and justified by the fact that, Therefore, negligible-polar phonons involved in Raman processes have nearly indistinguishable properties from those at the #sym.Gamma point. -#include "figure-discont.typ" - 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。 // Representation of these 18 phonons, and the shape of their Raman tensors could be determined in advance.) diff --git a/paper/todo.typ b/paper/todo.typ index 22003d4..8314e9a 100644 --- a/paper/todo.typ +++ b/paper/todo.typ @@ -31,7 +31,13 @@ - [ ] 英文 - [ ] 填充数据和引用 - [/] results - - [x] 总述 + - [/] 总述 + - [ ] 声子位置与实验对应 + - [x] 中文 + - [x] 英文 + - [ ] 调整语言 + - [ ] 调整画图 + - [ ] 每个位置有 21 个模式 - [/] 无缺陷 - [ ] 总述 - [x] Gamma 附近有 21 个模式,我们将它们分为强极性和弱极性