The quantum information network is important in establishing next-generation technology. In particular, maximal and long-distance entangled states are important in realizing a number of quantum information technologies, such as teleportation, key distribution and so forth. Entanglement swapping is a scheme that creates a long-distance network by using multiple short ones. Entanglement swapping protocols applied to non-maximal correlations have been thoroughly investigated by various people. Rather than providing any new analytic results, some examples of a numerical approach will be provided in this paper. In particular, the paper reveals the existence of different classes of coefficients that approximate the optimal outcome ( i.e. , the weaker average maximal entanglement between the two initial states). The new class of states is non-trivial in the sense that their coefficients are just as widely distributed as the coefficients of states satisfying optimality conditions are. Moreover, we will numerically examine entanglement swapping methods and show the distribution of optimal and general coefficients for three and four 2-level correlations.
The quantum information network is important in establishing next-generation technology. In particular, maximal and long-distance entangled states are important in realizing a number of quantum information technologies, such as teleportation, key distribution and so forth. Entanglement swapping is a scheme that creates a long-distance network by using multiple short ones. Entanglement swapping protocols applied to non-maximal correlations have been thoroughly investigated by various people. Rather than providing any new analytic results, some examples of a numerical approach will be provided in this paper. In particular, the paper reveals the existence of different classes of coefficients that approximate the optimal outcome ( i.e. , the weaker average maximal entanglement between the two initial states). The new class of states is non-trivial in the sense that their coefficients are just as widely distributed as the coefficients of states satisfying optimality conditions are. Moreover, we will numerically examine entanglement swapping methods and show the distribution of optimal and general coefficients for three and four 2-level correlations.
Recent successes in quantum technology have provided a number of powerful tools for viewing nature in terms of information. In particular, quantum information science has proved to be a useful way to greatly simplify the way the universe is viewed as well as treating the subject, an observer, and the object, the observed universe, on an equal footing. Several important applications in quantum technology such as communication, information processing, etc., use a distinctive property of entanglement. In this article, a numerical simulation is applied to a swapping measurement protocol involving two 3-level entangled states. A different condition, in non-maximal states, that approximates the optimal result (i.e., the weaker link between the two initial states) will be shown through a numerical method. This different class of states is distributed just as wide as the class yielding the optimal result. The result may be useful in establishing a long distance maximal entanglement that is often fragile and unstable due to noise.
Entanglement has recently been one of the most essential elements in the development of various quantum technologies. In fact, a swapping protocol was introduced to create a long-distance entanglement from multiple shorter ones. Extending the previous work, this paper provides a more detailed numerical analysis to help create long-distance entanglement out of the two non-maximal three-level states. Specifically, it shows that while the protocol does not always yield optimal results, namely, the weaker link, there is a substantial number of states that yield an optimal result. Moreover, we discuss the numerical approach in showing the existence of states that provide a result close to the optimal outcome, which may be useful in realizing the long-distance entanglement used in quantum technology.
Abstract: Entanglement has been one of the dominant aspects distinguishing quantum theory from its classical counterpart. Indeed, entanglement has played a central role in recent developments in quantum technology, such as quantum computing, key distribution, etc. In order to use entanglement in these situations, a particular form is often needed, namely the maximal case. Various techniques have been used to manipulate entangled states, especially between distant parties. Generating long-distance entanglement from multiple shorter states has been studied, and it has been shown that there exists a class of states that can achieve optimal entanglement resources. In this paper, the particular class of states that yields the weakest link is numerically examined. The findings reveal that the range of this class is limited but substantial. Keywords: Quantum entanglement, Numerical methods, Maximal states.
The realization of long-distance entanglement has been important in many quantum technologies, including quantum cryptography. In particular, a swapping protocol has been introduced for connecting multiple short networks to create a long-distance entangled pair. Building on previous work, this paper attempts to provide a numerical analysis of entanglement swapping of two 4-level states. While it is not always possible to have a weaker link between the two states (i.e., the optimal case), a substantial number of states satisfy the best scenario. Moreover, various numerical outcomes are shown to yield near-optimal results when a swapping protocol is applied. Recently, the subjective nature of physical reality has been discussed from the perspective of quantum theory. It is suggested that, similar to the energy and mass relation in relativity, an equivalence between mass and meaning in the mind may be derived. That is, the experience of mass may be different for observers with different mental knowledge.
The subjectivity seen in quantum theory has been the topic of major debate ever since the theory was first introduced about a century ago. The idea of treating the subject and the object independently has been difficult to accept in the science community; however, the subjective limit of knowledge has been discussed in philosophy for centuries. On the other hand, one of the important outcomes of recent studies of quantum theory is developing useful and practical applications from often controversial and philosophical debates such as the simultaneous existence of multiple states or superluminal influencing, which appears to violate the locality imposed by relativity. Establishing a long-distance correlation may be effective in a number of applications in quantum information technology. In this paper, an entanglement swapping scheme for three 2-level states is examined using numerical methods. In particular, it is studied that there is a class of non-maximal states that approximate the optimal outcome, namely, the weakest link.
Entanglement swapping is a key technology to realize long-distance quantum communication and build quantum networks, and has extensive and important applications in quantum information processing. In this paper, we propose a new algorithm to obtain entanglement swapping results, which is based on the idea of constructing new entangled states after entanglement swapping from all possible observation outcomes. We demonstrate the algorithm by the entanglement swapping between two bipartite entangled states, and derive the results of entanglement swapping between two 2-level Bell states, which are consistent with those obtained through algebraic calculations. Our work can provide new perspectives for thinking about the principles of quantum mechanics and trigger in-depth exploration of quantum mechanics principles and natural mysteries.