Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/81165

Title

Criteria for generalized macroscopic and mesoscopic quantum coherence

Author(s)

Cavalcanti, E. G.;  Reid, M. D.

Abstract

We consider macroscopic, mesoscopic, and 'S -scopic' quantum superpositions of eigenstates of an observable and develop some signatures for their existence. We define the extent, or size S of a superposition, with respect to an observable x, as being the range of outcomes of x predicted by that superposition. Such superpositions are referred to as generalized S -scopic superpositions to distinguish them from the extreme superpositions that superpose only the two states that have a difference S in their prediction for the observable. We also consider generalized S -scopic superpositions of coherent states. We explore the constraints that are placed on the statistics if we suppose a system to be described by mixtures of superpositions that are restricted in size. In this way we arrive at experimental criteria that are sufficient to deduce the existence of a generalized S -scopic superposition. The signatures developed are useful where one is able to demonstrate a degree of squeezing. We also discuss how the signatures enable a new type of Einstein-Podolsky-Rosen gedanken experiment.

Publication type

Journal article

Source

Physical Review A: Atomic, Molecular, and Optical Physics, Vol. 77, no. 6 (2008), article no. 062108

Publication year

2008

FOR Code(s)

0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics;  0204 Condensed Matter Physics;  0205 Optical Physics

Keyword(s)

Coherent light;  Coherent states;  Computer networks;  Eigenstates;  Einstein Podolsky Rosen;  EPR;  Forecasting;  Mesoscopic;  Quantum coherences;  Quantum superpositions;  Quantum theory;  Superconducting materials

Publisher

American Physical Society

ISSN

1050-2947

Publisher URL

http://dx.doi.org/10.1103/PhysRevA.77.062108

Copyright

Copyright © 2008 The American Physical Society.

Peer reviewed