| 查看: 1261 | 回复: 11 | |||
| 【奖励】 本帖被评价10次，作者zzgyb增加金币 10 个 | |||
| 当前主题已经存档。 | |||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||
[资源]
费米面及其构造
|
|||
|
Introduction The Fermi surface is the surface of constant energy in k space. The Fermi surface separates the unfilled orbitals from the filled orbitals, at absolute zero. The electrical properties of the metal are determined by the shape of the Fermi surface, because the current is due to changes in the occupancy of states near Fermi surface. The free electron Fermi surfaces were developed from spheres of radius kF determined by the valence electron concentration. Construction of free-electron Fermi surfaces The free electron Fermi surface for the an arbitrary electron concentration is shown in Fig.1.
Figure 1 These are Brillouin zones of a square lattice in two dimensions. The circle shown is a surface of constant energy for free electrons; it will be the Fermi surface for some particular value of the electron concentration. It is inconvenient to have sections of the Fermi surface that belong to the same
Figure 2 Brillouin zone appear detached one from another. The detachment can be repaired by a transformation to the first Brillouin zone. The procedure is known as mapping the Fermi surface in the reduced zone scheme. There is also another way to represent the Fermi surface in the reduced and periodic zone scheme. Fermi surfaces for free electrons are constructed by a procedure credited to Harrison, Fig.2. The reciprocal lattice points of a square lattice are determined, and free-electron sphere of radius appropriate to the electron concentration is drawn around each point. Any point in k space that lies within at least one sphere corresponds to an occupied state in the first zone. Points within at least two spheres correspond to occupied states in the second zone, and similarly for points in three or more spheres. In Fig.3,
Figure 3 the black square shown is the first Brillouin zone, the blue circle is the surface of constant energy for free electrons, and the shaded area represents occupied electron states. As we can see, the first zone is entirely occupied. In Fig.4,
Figure 4 the black square shown is the first Brillouin zone, the blue lines are the Fermi surfaces for free electrons on the second zone, and the shaded area represents occupied electron states. In Fig.5,
Figure 5 the black square shown is the first Brillouin zone, the blue lines are the Fermi surfaces for free electrons on the third zone, and the shaded area represents occupied electron states. In Fig.6,
Figure 6 the black square shown is the first Brillouin zone, the blue lines are the Fermi surfaces for free electrons on the fourth zone, and the shaded area represents occupied electron states. Thus, in Fig.7,
1st 2nd 3rd 4th Figure 7 we show the free electron Fermi surface, as viewed in the reduced zone scheme. The shaded areas represent occupied electron states. Parts of Fermi surface (blue lines) fall in the second, third, and fourth zones. The first zone is entirely occupied. In Fig.8,
Figure 8 we show the Fermi surface for free electrons in the second zone as drawn in the periodic scheme. The figure can be constructed by repeating the second zone of Fig.7 or directly from Harrison construction. In Fig.9,
Figure 9 we show the Fermi surface for free electrons in the third zone as drawn in the periodic scheme. The figure can be constructed by repeating the third zone of Fig.7 or directly from Harrison construction. In Fig.10,
Figure 10 we show the Fermi surface for free electrons in the fourth zone as drawn in the periodic scheme. The figure can be constructed by repeating the fourth zone of Fig.7 or directly from the Harrison construction. |
回复此楼» 收录本帖的淘帖专辑推荐
 科研技巧 |
» 猜你喜欢
光学工程学硕调剂信息
已经有32人回复
-
欢迎加入课题组
已经有0人回复
-
物理学I论文润色/翻译怎么收费?
已经有157人回复
-
散金币，求好运，祝面上顺利！
已经有79人回复
-
华东师范大学芯片设计徐珑真实水平咋样
已经有1人回复
-
调剂
已经有0人回复
-
【新加坡】纳米电子器件项目组有“联合培养博士生”名额
已经有0人回复
-
中德博士后2026项目5月30日截止- 国内博士后入站、德国两年全职
已经有0人回复
-
面向全球申请人的中德博士后2026项目5月30日截止- 国内博后入站德国两年全职
已经有0人回复
-
【新加坡】纳米电子器件项目组有“联合培养博士生”名额
已经有2人回复
-
重庆交大材料学院26年硕士招生复试实施细则已出。欢迎加入光子学微结构与器件课题组。
已经有0人回复
liuying287
禁言 (正式写手)
|
本帖内容被屏蔽 |
7楼2008-03-23 19:49:25
4楼2008-03-13 14:29:34
5