What is the significance of the Klein Paradox in particle physics?

[go quantum!]

The Klein Paradox is the name given to the following prediction of Klein Gordon's equations. If you send a current of electrons against a potential barrier of height V such that the energy of the incident electrons is less then V - m, you should observe a current of positrons coming out of the other side of the barrier.
Is this observed experimentally?

Actually, this is just one possible interpretation of the fact that we obtain a negative coefficient of transmission. We consider that a sufficiently high potential, in this particular case, V=E_inc + m, might create pairs of the incident particle and its antiparticle. The antiparticles have opposite charge, thus they will be compelled to pass the barrier. And that is why we observe the current of antiparticles coming out.
Is there other interpretations?

 

[Bill_K]

The concept of a potential well V(x) in relativity always leads to potential paradoxes. Here, an endless production of particle-antiparticle pairs out of seemingly nowhere. The solution is that V(x) must be maintained by an external energy source which supplies the energy needed for the particle creation.