Optical qudit-type entanglement creation at long distances by means of small cross-Kerr nonlinearities

Abstract

Entanglement represents an important resource for quantum information processing, but its generation itself requires physical resources that are limited. We propose a scheme for generating a wide class of entangled qudit-type states of optical field modes at sites separated by noisy medium when only weak optical nonlinearities are available at both sites. The protocol is also based on exploiting a weak probe field, transmitted between the sites and used for generation of quantum correlations between two spatially separated field modes. The idea of probabilistic entanglement enhancement by measurement is discussed, and corresponding scheme for measuring the probe field state with linear optics and photodetectors not resolving photon numbers is proposed. It is shown that the protocol is applicable in the case when decoherence, limited efficiency and dark counts of photodetectors, and uncertainty of nonlinear coupling constants are present.

References in corpus (7)

• A computable measure of nonclassicality for light
• Hybrid quantum repeater based on dispersive CQED interactions between matter qubits and bright coherent light
• The efficiencies of generating cluster states with weak non-linearities
• 2.23 GHz gating InGaAs/InP single-photon avalanche diode for quantum key distribution
• Weak non-linearities and cluster states
• Highly non-Gaussian states created via cross-Kerr nonlinearity
• Cross-Kerr interaction in a four-level atomic system

Cited by in corpus (2)

• Multi-state discrimination below the quantum noise limit at the single-photon level
• Data-pattern tomography of entangled states