2021/07/20 by X. Gutiérrez de la Cal, M. Alkhateeb, M. Pons +2 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1038/s41598-020-76065-7
published as Scientific Reports, 10:19225 (2020) Sci. Rep. (2020) 10:19225
arxiv created 2021/07/20 · arxiv updated 2021/07/21
We analyse a little known aspect of the Klein paradox. A Klein-Gordon boson appears to be able to cross a supercritical rectangular barrier without being reflected, while spending there a negative amount of time. The transmission mechanism is demonstrably acausal, yet an attempt to construct the corresponding causal solution of the Klein-Gordon equation fails. We relate the causal solution to a divergent multiple-reflections series, and show that the problem is remedied for a smooth barrier, where pair production at the energy equal to a half of the barrier's height is enhanced yet remains finite.