Wigner distribution behaviour in tunnelling through multi-barrier potentials
Marína Glasnáková
Abstract
Quantum tunnelling is a macroscopically measurable phenomenon that distinguishes quantum from classical physics. We study it through the Wigner quasiprobability dis- tribution and its negativity, which serves as a quantifier of non-classicality of quantum states. We model the tunnelling particle as a Gaussian wave packet evolving in one- dimensional single or double-barrier potentials. We find that the negativity is strongly enhanced at energies near the potential maxima, which correspond to classical unstable equilibrium states. For the double-barrier potentials, the negativity is further accentuated and long-lived due to the presence of quasibound resonant states temporarily trapped in- side the central well. This gives us insight that is invisible in the plane-wave limiting analysis.