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I think that the article should explain the relation of crystal momentum to the electron-phonon interaction as well as the translational symmetry in the Hamiltonian. I want to remove the extensive use of real in quotation marks. WilliamDParker 16:49, 10 November 2006 (UTC)
The crystal momentum is given by . The quantity denotes the wave vector. -- 132.199.98.122 16:18, 19 March 2007 (UTC)
Recently rewrote the article. Mostly this was for my own edification and understanding of the topic so clarifications would be welcome. A few notes: The first couple sentences are basically the same. Later on I wasn’t entirely convinced that the problem of finite momentum leading to electrons shooting out the sides of a crystal defines a real difference between regular and crystal momentum, so I canned the idea in the rewrite. I moved the old second paragraph under the “origins” section. Most of the rest of the previous article is reworked under “physical significance” which I was trying to write as a section that addresses how one might be able to think about crystal momentum intuitively. Pictures would be nice to add. I also removed the flags. Csmallw ( talk) 05:31, 27 July 2008 (UTC)
Perhaps a proof of the theorem d/dt(p_crystal)=F_ext is in order, since it is so often used? There is a very short and formal proof (due to Herbert Kroemer) in Charles Kittel, 'Introduction to Solid State Physics' 7th Edition, Appendix E, P. 646. -- Philipralph ( talk) 02:38, 14 June 2010 (UTC)
it does NOT follow from the finiteness of v_k that any crystal should be a conductor as the article now says. Insulators are such NOT because they scatter electrons strongly. Group velocities can be both positive and negative, and in a fully occupied band the two exactly cancel each other. 71.137.237.162 ( talk) 03:31, 23 December 2010 (UTC)
I think this article is not quite correct or too narrow: So in the first sentence it is said that crystal momentum refers to electrons. However, crystal momentum is also defined for phonons and magnons in crystal and is especially important for the description of their interaction. It would also be appropriate to derive it from more fundamental symmetries, namely the permutation symmetry of identical nuclei. This can be found e.g. in the appendices of the book by Ashcroft & Mermin. — Preceding unsigned comment added by 79.251.31.200 ( talk) 06:28, 8 October 2014 (UTC)
![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
I think that the article should explain the relation of crystal momentum to the electron-phonon interaction as well as the translational symmetry in the Hamiltonian. I want to remove the extensive use of real in quotation marks. WilliamDParker 16:49, 10 November 2006 (UTC)
The crystal momentum is given by . The quantity denotes the wave vector. -- 132.199.98.122 16:18, 19 March 2007 (UTC)
Recently rewrote the article. Mostly this was for my own edification and understanding of the topic so clarifications would be welcome. A few notes: The first couple sentences are basically the same. Later on I wasn’t entirely convinced that the problem of finite momentum leading to electrons shooting out the sides of a crystal defines a real difference between regular and crystal momentum, so I canned the idea in the rewrite. I moved the old second paragraph under the “origins” section. Most of the rest of the previous article is reworked under “physical significance” which I was trying to write as a section that addresses how one might be able to think about crystal momentum intuitively. Pictures would be nice to add. I also removed the flags. Csmallw ( talk) 05:31, 27 July 2008 (UTC)
Perhaps a proof of the theorem d/dt(p_crystal)=F_ext is in order, since it is so often used? There is a very short and formal proof (due to Herbert Kroemer) in Charles Kittel, 'Introduction to Solid State Physics' 7th Edition, Appendix E, P. 646. -- Philipralph ( talk) 02:38, 14 June 2010 (UTC)
it does NOT follow from the finiteness of v_k that any crystal should be a conductor as the article now says. Insulators are such NOT because they scatter electrons strongly. Group velocities can be both positive and negative, and in a fully occupied band the two exactly cancel each other. 71.137.237.162 ( talk) 03:31, 23 December 2010 (UTC)
I think this article is not quite correct or too narrow: So in the first sentence it is said that crystal momentum refers to electrons. However, crystal momentum is also defined for phonons and magnons in crystal and is especially important for the description of their interaction. It would also be appropriate to derive it from more fundamental symmetries, namely the permutation symmetry of identical nuclei. This can be found e.g. in the appendices of the book by Ashcroft & Mermin. — Preceding unsigned comment added by 79.251.31.200 ( talk) 06:28, 8 October 2014 (UTC)