996 research outputs found
Relativistic tunneling and accelerated transmission
We obtain the solutions for the tunneling zone of a one-dimensional
electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave
equation regime when the incoming wave packet exhibits the possibility of being
almost totally transmitted through the potential barrier. The conditions for
the occurrence of accelerated and, eventually, superluminal tunneling
transmission probabilities are all quantified and the problematic superluminal
interpretation originated from the study based on non-relativistic dynamics of
tunneling is overcome. The treatment of the problem suggests revealing insights
into condensed-matter experiments using electrostatic barriers in single- and
bi-layer graphene, for which the accelerated tunneling effect deserves a more
careful investigation.Comment: 10 pages, 1 figur
Delay time computation for relativistic tunneling particles
We study the tunneling zone solutions of a one-dimensional electrostatic
potential for the relativistic (Dirac to Klein-Gordon) wave equation when the
incoming wave packet exhibits the possibility of being almost totally
transmitted through the barrier. The transmission probabilities, the phase
times and the dwell times for the proposed relativistic dynamics are obtained
and the conditions for the occurrence of accelerated tunneling transmission are
all quantified. We show that, in some limiting cases, the analytical
difficulties that arise when the stationary phase method is employed for
obtaining phase (traversal) tunneling times are all overcome. Lessons
concerning the phenomenology of the relativistic tunneling suggest revealing
insights into condensed-matter experiments using electrostatic barriers for
which the accelerated tunneling effect can be observed.Comment: 17 pages, 4 figure
Non-classicality from the phase-space flow analysis of the Weyl-Wigner quantum mechanics
A fluid analog of the information flux in the phase-space associated to
purity and von Neumann entropy are identified in the Weyl-Wigner formalism of
quantum mechanics. Once constrained by symmetry and positiveness, the
encountered continuity equations provide novel quantifiers for non-classicality
(non-Liouvillian fluidity) given in terms of quantum decoherence, purity and
von Neumann entropy fluxes. Through definitions in the Weyl-Wigner formalism,
one can identify the quantum fluctuations that distort the classical-quantum
coincidence regime, and the corresponding quantum information profile, whenever
some bounded volume of the phase-space is specified. The dynamics of
anharmonic systems is investigated in order to illustrate such a novel paradigm
for describing quantumness and classicality through the flux of quantum
information in the phase-space.Comment: 11 pages, 1 figur
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