Tunable delay of Einstein–Podolsky–Rosen entanglement

Dah-Wei Chiou

Fuli Li, Muhammad Suhail Zubairy

Nikolett Német, T. Kiss, A. S. Parkins

A study of an open nondegenerate parametric oscillator is presented below threshold in the undepleted pump regime with time-delayed coherent feedback. The figure of merit is the two-mode squeezing spectrum measuring the strength of continuous-variable Einstein-Podolsky-Rosen-type entanglement between the down-converted modes in the output field as a function of frequency. Exploring different areas of the parameter space reveals the possibility of significantly enhanced entanglement with tunable characteristic frequency. This is a result of the emerging dynamical features that are only accessible due to delayed feedback. The system is very sensitive to phase matching, which can be adjusted by various parameters of the system and the feedback loop. In this way, sharp, resonancelike features are obtained that show a level of robustness against extraneous losses.

Michał Dąbrowski, Michal P. Parniak, Radosław Chrapkiewicz +1 more

Raman scattering emissive multimode quantum memory setup is presented. The memory enables storage of photonic position-momentum entanglement, demonstrating a time-delayed Einstein-Podolsky-Rosen paradox.

Paul Cummins

M. K. Olsen, P. D. Drummond

We show that two evanescently coupled ${\ensuremath{\chi}}^{(2)}$ parametric down-converters inside a Fabry-Perot cavity provide a tunable source of quadrature squeezed light, Einstein-Podolsky-Rosen (EPR) correlations and quantum entanglement. Analyzing the operation in the below threshold regime, we show how these properties can be controlled by adjusting the coupling strengths and the cavity detunings. As this can be implemented with integrated optics, it provides a possible route to rugged and stable EPR sources.