Recent experimental and theoretical works have reignited long-standing and controversial questions surrounding quantum tunneling times. Here we examine three currently-used tunneling time metrics, and propose a new metric, the tunneling flight time (TFT), based on weak-averaging, and we argue for its intuitive, natural utility as a tunneling time measure. The TFT is then shown to become equal to the Wigner phase time when the momentum-width of the incident wave packet is sufficiently narrow. Equipped with this new understanding of the tunneling time, we examine and comment on the recent tunneling time experiments of Ramos et al., we explore flight times in nonadiabatic avoided-crossing systems, and we examine the curious MacColl-Hartman effect in a relativistic framework to resolve outstanding questions about tunneling times, relativity, and superluminal signaling.
Host: Dvira Segal