We investigate the multiple teleportation with some nonmaximally entangled channels. The efficiencies of two multiple teleportation protocols, the separate multiple teleportation protocol (SMTP) and the global multiple teleportation protocol (GMTP), are calculated. We show that GMTP is more efficient than SMTP. PACS numbers: 03.67.Hk Quantum teleportation [1] is one of the most significant components in quantum information processing, which allows indirect transmission of quantum information between distant parties by using previously shared entan-glement and classical communication between them. Indeed , it is considered as a basic building block of quantum communication nowadays. Not only is it one of the most intriguing phenomena in the quantum world, but also a very useful tool to perform various tasks in quantum information processing and quantum computing [2, 3]. For example, controlled quantum gates are implemented by means of quantum teleportation, which is very important in linear optical quantum computation [4, 5]. Recently, the original scheme for teleporting a qubit has been widely generalized in many different ways [6, 7, 8, 9, 10, 11, 12, 13, 14]. In the previous telepor-tation protocols and in many other applications of tele-portation, we want to construct an unknown input state with unity fidelity at another location while destroying the original copy, which is always achieved if two parties share a maximally entangled state. However, it might happen that our parties do not share a maximally entangled state. This limitation can be overcome by distilling out of an ensemble of partially entangled states a maximally entangled one [15]. But this approach requires a large amount of copies of partially entangled states to succeed. Another way to achieve unity fidelity teleporta-tion with limited resources is based on the probabilistic quantum teleportation protocols of Refs. [6, 7, 8]. Recently, in an interesting work, Mod lawska and Grudka [16] showed that if the qubit is teleported several times via some nonmaximally entangled states, then the "errors" introduced in the previous teleportations can be corrected by the "errors" introduced in the following teleportations. Their strategy was developed in the framework of the scheme proposed in Ref.[5] for linear optical teleportation. In this paper, we show that this feature of the multiple teleportation of Ref.[16] is not * Electronic address: flyan@mail.hebtu.edu.cn restricted to the teleportation scheme stated in Ref.[5]. Based on the general teleportation language of the original proposal shown in Ref.[1], we compare the efficiencies of two multiple teleportation protocols, the separate multiple teleportation and the global multiple teleportation. In the former protocol, a complete teleportation including error correction is strictly executed by neighboring parties. On the other hand, in the latter protocol, all errors introduced in the teleportation are corrected by the final receiver. We find the global multiple teleportation is more efficient than...

Multi-hop teleportation has significant value due to long-distance delivery of quantum information. Many studies about multi-hop teleportation are based on Bell pairs, partially entangled pairs or W state. The possibility of multi-hop teleportation constituted by partially entangled pairs relates to the number of nodes. The possibility of multi-hop teleportation constituted by double W states is 4 9 n after n-hop teleportation. In this paper, a multi-hop teleportation scheme based on W state and EPR pairs is presented and proved. The successful possibility of quantum information transmitted hop by hop through intermediate nodes is deduced. The possibility of successful transmission is 2 3 n after n-hop teleportation.

Quantum multi-hop teleportation is important in the field of quantum communication. In this study, we propose a quantum multi-hop communication model and a quantum routing protocol with multihop teleportation for wireless mesh backbone networks. Based on an analysis of quantum multi-hop protocols, a partially entangled Greenberger--Horne--Zeilinger (GHZ) state is selected as the quantum channel for the proposed protocol. Both quantum and classical wireless channels exist between two neighboring nodes along the route. With the proposed routing protocol, quantum information can be transmitted hop by hop from the source node to the destination node. Based on multi-hop teleportation based on the partially entangled GHZ state, a quantum route established with the minimum number of hops. The difference between our routing protocol and the classical one is that in the former, the processes used to find a quantum route and establish quantum channel entanglement occur simultaneously. The Bell state measurement results of each hop are piggybacked to quantum route finding information. This method reduces the total number of packets and the magnitude of air interface delay. The deduction of the establishment of a quantum channel between source and destination is also presented here. The final success probability of quantum multi-hop teleportation in wireless mesh backbone networks was simulated and analyzed. Our research shows that quantum multi-hop teleportation in wireless mesh backbone networks through a partially entangled GHZ state is feasible.Keywords: wireless mesh backbone network, multi-hop teleportation, partially entangled GHZ state, quantum routing protocol PACS: 03.67.Hk, 03.65.Ud IntroductionQuantum communication technology is a popular subject of research in the field of quantum information [1][2][3][4][5]. There are two methods to transmit quantum information between nodes. One involves the direct transfer of quantum states, whereas the other facilitates the indirect transfer of such states through quantum teleportation. Considering that qubits are sensitive to the environment and, hence, that some loss of information can occur, when quantum information needs to be transferred between two

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