Talk:Klein paradox

message: Please explain, why the wavefunction  \psi  is now not a bispinor! Where are the coupled differential equations from the Dirac-equation?
141.89.36.156 (talk) 13:59, 2 July 2014 (UTC)
thread_title:  Massless particles 

message: While the authors of the recent publications did explain what the significance of the spurious wave
is, they cannot possibly be said to have "resolved" this paradox. To resolve a paradox requires that the paradox should still be confusing at the time of publication.
Historically, the Klein paradox was important in demonstrating that a single-particle Dirac equation is inconsistent, and antiparticles are really required. This is its main historical purpose. It was resolved by Dirac, Klein, Heisenberg and whoever else did second quantization way back when. The recent publication is an analysis of the significance of Klein's solution. While it is interesting, and worth citing, it is absurd to say that the paper "resolved" the paradox just because the word "resolution" appears in the title, with the meaning in "the resolution of my monitor is 760 by 1200".
Likebox 02:53, 30 September 2007 (UTC)
thread_title:  Give Credit Where Credit Is Due 

message: I like the simple model with a massless two-component fermion. However, instead of considering motion along the x-axis, the argument would become even clearer when using the motion along the z-axis as the Pauli Matrix sigma_z is diagonal, in contrast to sigma_x. 195.126.85.141 (talk) 15:25, 11 October 2010 (UTC)
thread_title:  Use motion along z instead of x 

message: ::J_i=\psi_i^\dagger \sigma_x \psi_i^\dagger , i=1,2 \,
Shouldn't it rather be
::J_i=\psi_i^\dagger \sigma_x \psi_i , i=1,2 \,
? 
Sigi E (talk) 09:31, 17 January 2011 (UTC)
replies: text: Yup, fixed - thank you. Feel free to be bold in fixing things yourself. - 2/0 (cont.) 21:14, 17 January 2011 (UTC)
thread_title:  Probability current 

message: For the region II solution as given one has k<0.
The region II solution for k>0 imho should be:
::\psi_2=Be^{ikx}\left( \begin{matrix} -1 \\ 1\end{matrix} \right) ,\quad k=V_0-E_0  \,
This leaves us with A=0, which is confusing, and A'=B, which is pair creation.
I believe real-valued wave functions are needed.
Please give your comment. 
Aoosten (talk) 23:35, 15 December 2011 (UTC)
thread_title:  Region II solution 

message: It appears that, if I fire a wavepacket at this barrier, then the wavepacket will tunnel through just like the plane waves. On the far side of the barrier, its group velocity will be maintained. Also, due to charge conservation it will obviously have the same charge as the original wave (I have heard people say that Klein tunneling turns the electron into a positron (hole), but that seems suspicious). I suspect this has to do with some of the ambiguities about electron holes...
Does anyone know of some good research into this topic?
--Nanite (talk) 13:42, 20 May 2013 (UTC)
thread_title:  What is the nature of the propogating "positron" state? 

message: Any problem if I rewrite the whole article? I think it needs a massive and a non massive case, a step barrier would be more illustrative and maybe it needs an experimental section (graphene).MaoGo (talk) 13:58, 23 October 2017 (UTC)
thread_title:  Revamp 

message: Echoing some of the statements above, the article needs a new section describing how the original paradox arose, namely, in the context of "nuclear electrons" or the hypothetical electrons people believed were confined within the nucleus until the neutron was discovered (see Discovery of the neutron).  There are two main missing elements - (1) a discussion of what people believed from the paradox at the time, namely the curious phrase in Gamow's 1931 monograph "the electron transforms to one of negative mass and escapes", and (2) the issue was hotly debated by Gamow, Bohr, etc. at the time.  (and (3) how the paradox was eventually resolved...)  The paradox was a main issue for the nuclear electrons hypothesis.  The article mentions the issue in the lede (which, I think I wrote that...), but needs a better discussion in the article.  As it stands, the article launches into an obscure technical analysis that would be of interest to those who are experts in relativistic quantum mechanics (i.e., few people - I know quite a bit about the topic, and even I find the present discussion obscure!). Bdushaw (talk) 02:09, 16 February 2020 (UTC)
thread_title: The original issue with the Klien paradox