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Energy-time entangled biphoton source plays a great role in quantum communication, quantum metrology and quantum cryptography due to its strong temporal correlation and capability of nonlocal dispersion cancellation. As a quantum effect, nonlocal dispersion cancellation is further proposed as an alternative way for nonlocality test of continuous variable entanglement via the violation of Bell-like inequality proposed by Wasak et al. [Phys. Rev. A, 82, 052120 (2010)]. However, to date there is no experimental report either on the inequality violation or on a nonlocal detection with single-photon detectors at long-distance transmission channel, which is key for a true nonlocality test. In this paper, we report an experimental realization of a violation of the inequality after 62km optical fiber transmission at telecom wavelength with a nonlocal detection based on event timers and cross-correlation algorithm, which indicates a successful nonlocal test of energy-time entanglement. This work provides a new feasibility for the strict test of the nonlocality for continuous variables in both long-distance communication fiber channel and free space.
We derive an inequality bounding the strength of temporal correlations for a pair of light beams prepared in a separable state and propagating through dispersive media with opposite signs of group velocity dispersion. The presented inequality can be
Recently the engineering of the entanglement for photon pairs generated during the spontaneous parametric down conversion process (SPDC) can be achieved via manipulation of pump wavelength behind a c{hi}(2)-based type II SPDC process [1]. Such effect
Dispersion and its cancellation in entanglement-based nonlocal quantum measurements are of fundamental and practical interests. We report the first demonstration of cancellation of femtosecond-level dispersion by inverting the sign of the differentia
We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometers unique correlation dependence on the anti-diagonal elements of the density matrix, which have
Nonlocal gate operation is based on sharing an ancillary pair of qubits in perfect entanglement. When the ancillary pair are partially entangled, the efficiency of the gate operation drops. Using general transformations, we devise probabilistic nonlo