The action of a channel on a quantum system, when non trivial, always causes deterioration of initial quantum resources, understood as the entanglement initially shared by the input system with some reference purifying it. One effective way to measure such a deterioration is by measuring the loss of coherent information, namely the difference between the initial coherent information and the fin...

Entanglement-based quantum science exploits subtle properties of quantum mechanics into applications such as quantum computing, sensing, and metrology. The emerging route for quantum computing applications, which calls for ultracompact, integrated, and scalable architecture, aims at onchip entangled qubits. In this context, quantum entanglement among atomic qubits was achieved via cold-controll...

The violation of Bell's theorem is a very simple way to see that there is no underlying classical interpretation of quantum mechanics. The measurements made on the photons shows that light signal (information) could travel between them, hence completely eliminating any chance that the result was due to anything other than entanglement. Entanglement has been studied extensively for understanding...

Entanglement is the essential feature of quantum mechanics. Notably, observers of two or more entangled particles will find correlations in their measurement results that cannot be explained by classical statistics. To make it a useful resource, particularly for scalable long-distance quantum communication, the heralded generation of entanglement between distant massive quantum systems is neces...

Since the introduction of the paradox of Einstein, Podolsky, and Rosen @1# and Schrödinger’s cat @2#, the entanglement of quantum states, i.e., the ability of composite quantum systems to exhibit nonlocal correlations, has been one of the most fascinating consequences of the quantum formalism. Today the entanglement also serves as a basic resource of quantum information theory @3#, which is bas...

Bennett et al. showed that allowing shared entanglement between a sender and receiver before communication begins dramatically simplifies the theory of quantum channels, and these results suggest that it would be worthwhile to study other scenarios for entanglement-assisted classical communication. In this vein, the present paper makes several contributions to the theory of entanglement-assiste...

This article is intended to be a pedagogical review of the recent studies of quantum entanglement in many-body systems. The basic concepts of entanglement for pure and mixed states are introduced in an intuitive approach. We will see that in the weakly interacting BEC and BCS superconductivity theories, the pair of particles with momentum k and −k are entangled but they are not correlated with ...

Optical entanglement is a key requirement for many quantum communication protocols. Conventionally entanglement is formed between two distinct beams, with the quantum correlations being measured at separate locations. We show entanglement between the modes within one beam. Our technique is particularly elegant and a major advance towards practical systems with minimum complexity. We demonstrate...

Entanglement is believed to be crucial in macroscopic physical systems for understanding the collective quantum phenomena such as quantum phase transitions. We start from and solve exactly a novel Yang-Baxter spin-1/2 chain model with inhomogeneous and anisotropic short-range interactions. For the ground state, we show the behavior of neighboring entanglement in the parameter space and find tha...

We address the following criterion for quantifying the quantum information resources: classically simulable vs. classically non-simulable information processing. This approach gives rise to existence of a deeper level of quantum information processing–which we refer to as " quantum communication channel ". We particularly show, that following the recipes of the standard theory of entanglement m...