A quantum channel is derived for continuous variable teleportation which is performed by means of an arbitrary entangled state and the standard protocol. When a Gaussian entangled state such as a two-mode squeezed-vacuum state is used, the continuous variable teleportation is equivalent to the thermalizing quantum channel. Continuous variable dense coding is also considered. Both the continuous variable teleportation and the continuous variable dense coding are characterized by the same function determined by the entangled state and the quantum measurement.
Bidirectional controlled teleportation by using 5-qubit states: A generalized view
最近，使用5-qubit状态的双向受控完美隐形传态被报道在（Int. J. Theor.（2013）DOI 10.1007/s10773-013-1484-8和同上，（2013）DOI 10.1007/s10773-012-1208-5）。本文证明了存在一类5比特量子态可用于双向受控隐形传态。三个报告的情况中有两个是所提出的5-qubit量子态的特殊情况，其中一个不是严格的受控双向量子隐形传态的情况。此外，我们已经表明，原则上可以为此目的构建无限多个5量子位量子态。我们还表明，这个想法可以扩展到双向控制概率隐形传态。本文还讨论了该方案及其改进方案在实现量子遥控和量子密码学方面的一些潜在应用。
Quantum channels with correlated noise and entanglement teleportation
受C. Macchiavello和G. M. Palma关于纠缠增强的信息在具有相关噪声的量子信道上传输的研究，我们证明了J.Lee和M. S. Kim给出了两个不相关的广义去极化通道。为了寻找一种能产生两个相关广义去极化信道的隐形传态方案，我们发现了一种新的隐形传态方案，它允许人们在不减少纠缠量的情况下了解纠缠纯输入态中的纠缠.
By leveraging shared entanglement between a pair of qubits, one can teleport a quantum state from one particle to another. Recent advances have uncovered an intrinsically many-body generalization of quantum teleportation, with an elegant and surprising connection to gravity. In particular, the teleportation of quantum information relies on many-body dynamics, which originate from strongly-interacting systems that are holographically dual to gravity; from the gravitational perspective, such quantum teleportation can be understood as the transmission of information through a traversable wormhole…
We introduce a generalized concept of quantum teleportation in the framework of quantum measurement and reversing operation. Our framework makes it possible to find an optimal protocol for quantum teleportation enabling a faithful transfer of unknown quantum states with maximum success probability up to the fundamental limit of the no-cloning theorem. Moreover, an optimized protocol in this generalized approach allows us to overcome noise in quantum channel beyond the reach of existing teleportation protocols without requiring extra qubit resources. Our proposed framework is applicable to mult…
Very recently, Lee et al. proposed the first secure quantum teleporation protocol, where quantum information shared by an arbitrary number of senders can be transferred to another arbitrary number of receivers. Here, by introducing quantum walks, a novel secure (n,m) quantum teleportation of shared quantum secret between n senders and $m$ receivers is presented. Firstly, two kinds of (n,2) teleportation schemes are proposed by n-walker quantum walks on the line, the first walker of which is driven by three coins, respectively, based on two kinds of coin operators: the homogeneous coins and the…
We propose a scheme of repeated generalized Bell state measurement (GBSM) for probabilistic quantum teleportation of single qubit state of a particle (say, 0) using 3-qubit non-maximally entangled (NME) GHZ state as a quantum channel. Alice keeps two qubits (say, 1 and 2) of the 3-qubit resource and the third qubit (say, 3) goes to Bob. Initially, Alice performs GBSM on qubits 0 and 1 which may lead to either success or failure. On obtaining success, Alice performs projective measurement on qubit 2 in the eigen basis of $σ_{x}$. Both these measurement outcomes are communicated to Bob classical…
Quantum superpositions of coherent states are produced both in microwave and optical domains, and are considered realizations of the famous "Schrödinger cat" state. The recent progress shows an increase in the number of components and the number of modes involved. Our work creates a theoretical framework for treatment of multicomponent two-mode Schrödinger cat states. We consider a class of single-mode states, which are superpositions of $N$ coherent states lying on a circle in the phase space. In this class we consider an orthonormal basis created by rotationally-invariant circular states (RI…
In this work, we study the local distinguishability of maximally entangled states (MESs). In particular, we are concerned with whether any fixed number of MESs can be locally distinguishable for sufficiently large dimensions. Fan and Tian \emph{et al.} have already obtained two satisfactory results for the generalized Bell states (GBSs) and the qudit lattice states when applied to prime or prime power dimensions. We construct a general twist-teleportation scheme for any orthonormal basis with MESs that is inspired by the method used in [Phys. Rev. A \textbf{70}, 022304 (2004)]. Using this tele…
Reliable entangling gates for qubits encoded in single-photon states represent a major challenge on the road to scalable quantum computing architectures based on linear optics. In this work, we present two approaches to develop high-fidelity, near-deterministic controlled-sign-shift gates based on the techniques of quantum gate teleportation. On the one hand, teleportation in a discrete-variable setting, i.e., for qubits, offers unit-fidelity operations but suffers from low success probabilities. Here, we apply recent results on advanced linear optical Bell measurements to reach a near-determi…
The states of W-class as shared resources for perfect teleportation and superdense coding
我们知道，三量子比特系统的态有两类：GHZ类和W类。本文考虑W类态的隐形传态和超密集编码，并将其推广到多粒子系统。首先，我们描述了两个转换的共享资源的隐形传态和超密集编码，这使得许多新的协议，从一些已知的。作为这些变换的应用，我们得到了W类态适合于理想隐形传态和超密编码的一个充要条件。作为另一个应用，我们发现状态$|W>_{123}={1/2}(|100>_{123}+|010>_{123}+\sqrt{2}|001>_{123})$可以通过发送两个量子比特来传输三个经典比特，这是P.Agrawal和A. Pati [Phys. Rev. A待出版]。我们将W类的态推广到高维的多量子比特系统和多粒子系统。我们提出了两个利用多量子比特系统的W态进行隐形传态和超密集编码的协议，推广了P.Agrawal和A.帕蒂我们得到了将多量子比特系统的W态分割成两个子系统的最优方法，使得它们之间的纠缠达到最大值。
Bidirectional quantum teleportation is a fundamental protocol for exchanging quantum information between two parties. Specifically, the two individuals make use of a shared resource state as well as local operations and classical communication (LOCC) to swap quantum states. In this work, we concisely highlight the contributions of our companion paper [Siddiqui and Wilde, arXiv:2010.07905]. We develop two different ways of quantifying the error of nonideal bidirectional teleportation by means of the normalized diamond distance and the channel infidelity. We then establish that the values given …
Since the initial discovery of quantum teleportation, it is devoted to transferring unknown quantum states from one party to another distant partner. However, in the scenarios of remote sensing, what people truly care about is the information carried by certain parameters. The problem of multiparameter estimation in the framework of qutrit teleportation under amplitude damping (AD) noise is studied. Particularly, two schemes are proposed to battle against AD noise and enhance the precision of multiparameter estimation by utilizing weak measurement (WM) and environment-assisted measurement (EAM…
In this chapter a quantum communication protocol with use of repeaters is presented. The protocol is constructed for qudits i.e. the generalized quantum information units. One-dit teleportation is based on the generalized Pauli-Z (phase-flip) gate's correction. This approach avoids using Pauli-X and Hadamard gates unlike in other known protocols based on quantum repeaters which were constructed for qubits and qudits. It is also important to mention that the repeaters based on teleportation protocol, described in this chapter, allow a measurement in the standard base (what simplifies the measur…
Quantum Defect Analysis and Target-Orbit-Directed Correction via the Purpose-Oriented Framework: Applications to Entanglement Repairability and Teleportation Activation
Harbin Engineering University（哈尔滨工程大学）；Central South University（中南大学）；Zhejiang University（浙江大学）
