The quantum backflow effect is a counterintuitive behavior of the probability current of a free particle, which may be negative even for states with vanishing negative momentum component. Here, we address the notion of nonclassicality arising from the backflow effect, i.e. from the negativity of the probability current, and analyze its relationships with the notion of nonclassicality based on the negativity of the Wigner function. Our results show that backflow is linked to a different, and in fact more restrictive, notion of nonclassicality, the negativity of the Wigner function being only a necessary prerequisite for its occurrence. This hierarchical structure may be confirmed by looking at the addition of thermal noise, which more easily destroys the negativity of the probability current than the negativity of the Wigner function itself.
Quantum backflow effect and nonclassicality / F. Albarelli, T. Guaita, M.G.A. Paris. - In: INTERNATIONAL JOURNAL OF QUANTUM INFORMATION. - ISSN 0219-7499. - 14:7(2016 Oct).
|Titolo:||Quantum backflow effect and nonclassicality|
ALBARELLI, FRANCESCO (Primo)
PARIS, MATTEO (Ultimo)
|Parole Chiave:||Backflow effect; nonclassicality; quasiprobability distributions; Wigner function; physics and astronomy (miscellaneous)|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||ott-2016|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1142/S0219749916500325|
|Appare nelle tipologie:||01 - Articolo su periodico|