Relativistic Quantum Field Theory Approach to Electron Wavepacket Tunneling: a Fully Causal Process
Résumé
Recent results on electron tunneling across a potential barrier, inferred from
observations or obtained from theoretical models, have suggested superluminal
or instantaneous barrier traversal times. In this work we investigate
relativistic wavepacket dynamics for an electron tunneling through a potential
barrier employing space-time resolved solutions to relativistic quantum field
theory (QFT) equations. We prove by linking the QFT property of
microcausality to the wavepacket behavior that the tunneling dynamics is
fully causal, precluding instantaneous or superluminal effects. We illustrate
these results by performing numerical computations for an electron tunneling
through a potential barrier for standard tunneling as well for Klein
tunneling. In all cases (Klein tunneling \ or regular tunneling across a
standard or a supercritical potential) the transmitted wavepacket remains in
the causal envelope of the propagator, even when its average position lies
ahead of the average position of the corresponding freely propagated wavepacket.
Domaines
Physique Quantique [quant-ph]Origine | Fichiers produits par l'(les) auteur(s) |
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