In distributed systems based on the Quantum Recursive Network Architecture, quantum channels and quantum memories are used to establish entangled quantum states between node pairs. Such systems are robust against attackers that interact with the quantum channels. Conversely, weaknesses emerge when an attacker takes full control of a node and alters the configuration of the local quantum memory,...

The newfound importance of “entanglement as a resource” in quantum computation and quantum communication behooves us to quantify it in as many distinct ways as possible. Here we explore a new quantification of entanglement of a general (mixed) quantum state for a bipartite system, which we name entanglement of assistance. We show it to be the maximum of the average entanglement over all ensembl...

In this paper we provide an operational method to detect multipartite entanglement in ensemble-based quantum computing. This method is based on the concept of entanglement witness. We decompose the entanglement witness for each class of multipartite entanglement into nonlocal operations in addition to local measurements. Individual single qubit measurements are performed simultaneously, hence c...

Entanglement is the key element for many experiments in quantum communication and information. Especially for future applications like quantum networks or the quantum repeater it is mandatory to achieve entanglement also between separated quantum processors. For this purpose, entanglement between different quantum objects like atoms and photons forms the interface between atomic quantum memorie...

We generalize previously proposed conditions each measure of entanglement has to satisfy. We present a class of entanglement measures that satisfy these conditions and show that the Quantum Relative Entropy and Bures Metric generate two measures of this class. We calculate the measures of entangle-ment for a number of mixed two spin 1/2 systems using the Quantum Relative Entropy, and provide an...

ABSTRACT: Quantum information sheds new light on quantum systems, complementary to the traditional point of view of energy. A key notion is entanglement, which measures quantum correlations within the system. Understanding entanglement of ground states is crucial to efficiently represent such many-body states using a small number of variational parameters. This is but one example of very powerf...

Using well known duality between quantum maps and states of composite systems we introduce the notion of Schmidt number of a quantum channel. It enables one to define classes of quantum channels which partially break quantum entanglement. These classes generalize the well known class of entanglement breaking channels.

Developments in quantum information science rely critically on entanglement, as its distribution between different parties enables quantum communication protocols, such as quantum key distribution or teleportation. This talk focused on two different ways to generate heralded entanglement between matter systems, a critical reqiurement for scalable quantum networking.

Entanglement provides an essential resource for quantum computation, quantum communication, and quantum networks. How to conveniently and efficiently realize the generation, distribution, storage, retrieval, and control of multipartite entanglement is the basic requirement for realistic quantum information processing. Here, we present a theoretical proposal to efficiently and conveniently achie...

We explicitly model entanglement as a kind of parallelism under the framework of reversible quantum computing. A sound and complete axiomatization is founded. Different to modeling of entanglement in quantum computing, the shadow constant is unnecessary. And also, as a kind of parallelism, entanglement merge is also quite different.