Europhys. Lett.
Volume 76, Number 5, December 2006
Page(s) 746 - 752
Section General
Published online 03 November 2006
Europhys. Lett., 76 (5), pp. 746-752 (2006)
DOI: 10.1209/epl/i2006-10354-7

Generalized entanglement as a natural framework for exploring quantum chaos

Y. S. Weinstein1 and L. Viola2

1  Quantum Information Science Group, Mitre - Eatontown, NJ 07724, USA
2  Department of Physics and Astronomy, Dartmouth College - Hanover NH 03755, USA

received 25 July 2006; accepted in final form 9 October 2006
published online 3 November 2006

We demonstrate that generalized entanglement (BARNUM et al. , Phys. Rev. A, 68 (2003) 032308) provides a natural and reliable indicator of quantum chaotic behavior. Since generalized entanglement depends directly on a choice of preferred observables, exploring how generalized entanglement increases under dynamical evolution is possible without invoking an auxiliary coupled system or decomposing the system into arbitrary subsystems. We find that, in the chaotic regime, the long-time saturation value of generalized entanglement agrees with random matrix theory predictions. For our system, we provide physical intuition into generalized entanglement within a single system by invoking the notion of extent of a state. The latter, in turn, is related to other signatures of quantum chaos.

03.67.Mn - Entanglement production, characterization, and manipulation.
03.65.Ud - Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.).
05.45.Mt - Quantum chaos; semiclassical methods.

© EDP Sciences 2006