Position versus momentum

Milena D’Angelo, Yanhua H. Shih

Differences between two-photon imaging and its classical simulation are discussed. Quantum entanglement allows simultaneous momentum-momentum and position-position correlations. A quantum image may have spatial resolution beyond the diffraction limit. Classical simulations can never achieve that.

Mark Burgess

Wojciech Jaworski, David M. Wardlaw

Our previous results [Phys. Rev. A 37, 2843 (1988)], based on the concept of sojourn time, for the transmission and reflection time delays in one-dimensional scattering by a potential barrier are compared to the corresponding results of E. H. Hauge, J. P. Falck, and T. A. Fjedly [Phys. Rev. B 36, 4203 (1987)], based on the idea of following the time evolution of the mean position of wave packets. It is shown that the mean-position approach agrees with the more general sojourn-time approach in the limit of well-defined momentum, and that, in general, the two approaches appear to be related in a classical-like manner.

Paul Busch, PEKKA J. LAHTI, Juha-Pekka Pellonpää +1 more

Razieh Pakniat, Mohammad Kazem Tavassoly, Mohammad Hossein Zandi

Abstract In this paper we have studied the dynamical evolution of Shannon information entropies in position and momentum spaces for two classes of (nonstationary) atom-field entangled states, which are obtained via the Jaynes–Cummings model and its generalization. We have focused on the interaction between two- and Ξ-type three-level atoms with the single-mode quantized field. The three-dimensional plots of entropy densities in position and momentum spaces are presented versus corresponding coordinates and time, numerically. It is observed that for particular values of the parameters of the systems, the entropy squeezing in position space occurs. Finally, we have shown that the well-known BBM (Beckner, Bialynicki-Birola and Mycielsky) inequality, which is a stronger statement of the Heisenberg uncertainty relation, is properly satisfied.