Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/50060

Download PDF (Published version) (Adobe Acrobat PDF, -1 bytes)

Title

Critical fluctuations and entanglement in the nondegenerate parametric oscillator

Author(s)

Dechoum, K.;  Drummond, P. D.;  Chaturvedi, S.;  Reid, M. D.

Abstract

We present a fully quantum mechanical treatment of the nondegenerate optical parametric oscillator both below and near threshold. This is a nonequilibrium quantum system with a critical point phase transition, that is also known to exhibit strong yet easily observed squeezing and quantum entanglement. Our treatment makes use of the positive P representation and goes beyond the usual linearized theory. We compare our analytical results with numerical simulations and find excellent agreement. We also carry out a detailed comparison of our results with those obtained from stochastic electrodynamics, a theory obtained by truncating the equation of motion for the Wigner function, with a view to locating regions of agreement and disagreement between the two. We calculate commonly used measures of quantum behavior including entanglement, squeezing, and Einstein-Podolsky-Rosen (EPR) correlations as well as higher order tripartite correlations, and show how these are modified as the critical point is approached. These results are compared with those obtained using two degenerate parametric oscillators, and we find that in the near-critical region the nondegenerate oscillator has stronger EPR correlations. In general, the critical fluctuations represent an ultimate limit to the possible entanglement that can be achieved in a nondegenerate parametric oscillator.

Publication type

Journal article

Source

Physical Review A, Vol. 70, no. 5 (2004), article no. 053807

Publication year

2004

FOR Code(s)

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

Keyword(s)

Approximation theory;  Computer simulation;  Correlation methods;  Einstein-Podolsky-Rosen;  Electrodynamics;  EPR;  Parametric oscillators;  Phase transitions;  Random processes;  Second harmonic generation;  Conjugate beams;  Critical fluctuations;  Phase spaces;  Semiclassical theory;  Quantum theory

Publisher

American Physical Society

ISSN

1050-2947

Publisher URL

http://dx.doi.org/10.1103/PhysRevA.70.053807

Copyright

Copyright © 2004 The American Physical Society. Published version of this paper reproduced here in accordance with the copyright policy of the publisher.

Full text

Peer reviewed