Abstract The development of quantum communication technologies has made the efficient transmission and processing of quantum states increasingly important. This paper first introduces a traditional multi-hop quantum teleportation scheme based on simultaneous entanglement swapping(SES). In this scheme, different quantum channels are used for odd-hop and even-hop quantum teleportation, respectively. The specific quantum communication processes of two-hop, three-hop, and four-hop are introduced in turn, and the transmission law of n-hop quantum teleportation is summarized. On this basis, a multi-level hierarchical simultaneous entanglement swapping(MHSES) scheme for multi-hop quantum teleportation is further proposed, which is achieved by dividing the multi-hop quantum network into multiple segments with multiple levels of processing. In each level, the intermediate nodes only need to send the measurement results to the nodes at the end of the segment, thus greatly reducing the forwarding of classical information. IBM Qiskit was used to simulate the operation of these two schemes in ideal and noisy environments. Finally, the proposed scheme is compared with the existing conventional quantum teleportation schemes, and the results show that the proposed scheme achieves better results in terms of reduced classical resource consumption and reduced time delay.
Abstract The development of quantum communication technologies has made the efficient transmission and processing of quantum states increasingly important. This paper first introduces a traditional multi-hop quantum teleportation scheme based on simultaneous entanglement swapping(SES). In this scheme, different quantum channels are used for odd-hop and even-hop quantum teleportation, respectively. The specific quantum communication processes of two-hop, three-hop, and four-hop are introduced in turn, and the transmission law of n-hop quantum teleportation is summarized. On this basis, a multi-level hierarchical simultaneous entanglement swapping(MHSES) scheme for multi-hop quantum teleportation is further proposed, which is achieved by dividing the multi-hop quantum network into multiple segments with multiple levels of processing. In each level, the intermediate nodes only need to send the measurement results to the nodes at the end of the segment, thus greatly reducing the forwarding of classical information. IBM Qiskit was used to simulate the operation of these two schemes in ideal and noisy environments. Finally, the proposed scheme is compared with the existing conventional quantum teleportation schemes, and the results show that the proposed scheme achieves better results in terms of reduced classical resource consumption and reduced time delay.
Entanglement swapping is a key technology for multi-hop communication based on entanglement in quantum networks. However, the end-to-end delay of the traditional sequential entanglement swapping (SEQES) grows rapidly with the increase of network scale. To solve this problem, we first propose a low-delay multi-particle simultaneous entanglement swapping (SES) scheme to establish the remote four-particle Greenberger–Horne–Zeilinger (GHZ) channel states for the bidirectional teleportation of three-particle GHZ states, in which the intermediate nodes perform Bell state measurements, send the measurement results and the Bell state type to the user node Bob (or Alice) through classical channel simultaneously. Bob (or Alice) only needs to carry out a proper unitary operation according to the information he (or she) has received. Further, we put forward a hierarchical simultaneous entanglement swapping (HSES) scheme to reduce the classical information transmission cost, which is composed of level-1 SES and level-2 SES (schemes). The former is an inner segment SES, and the latter is an inter segments SES. Theoretical analysis and simulation results show the HSES can obtain the optimal performance tradeoff between end-to-end delay and classical cost.
Abstract Combined with hierarchy simultaneous entanglement swapping, the scheme of the multi-hop quantum teleportation (QT) is proposed by using multi-pair Bell states. The scheme consists of two levels based on simultaneous entanglement swapping, namely Level-1 and Level-2. The former realizes simultaneous entanglement swapping of the inner segment, while the latter completes simultaneous entanglement swapping of the inter segment. Besides, the effect of four different types of noise (phase-damping, amplitude-damping, phase-flip, and bit-flip noise) on our scheme is analyzed by calculating the fidelity and concurrence. The results indicate that the fidelity and concurrence are related to the amplitude parameter, decoherence rate and number of nodes. Furthermore, compared with the scheme of the multi-hop QT adopting simultaneous entanglement swapping, our scheme can greatly reduce classical communication cost, and shows that the optimal classical communication cost can be obtained by selecting different segmentation methods.
Abstract Implementing quantum wireless multi-hop network communication is essential to improve the global quantum network system. In this paper, we employ eight-level GHZ states as quantum channels to realize multi-hop quantum communication, and utilize the logical relationship between the measurements of each node to derive the unitary operation performed by the end node. The hierarchical simultaneous entanglement switching (HSES) method is adopted, resulting in a significant reduction in the consumption of classical information compared to multi-hop quantum teleportation (QT) based on general simultaneous entanglement switching (SES). In addition, the proposed protocol is simulated on the IBM Quantum Experiment platform (IBM QE). Then, the data obtained from the experiment are analyzed using quantum state tomography, which verifies the protocol’s good fidelity and accuracy. Finally, by calculating fidelity, we analyze the impact of four different types of noise (phase-damping, amplitude-damping, phase-flip and bit-flip) in this protocol.
Entanglement swapping (ES) based multi-hop quantum information transmission is a fundamental way to realize long-distance quantum communication. However, in the conventional quantum networks, the entanglement in one degree of freedom (DOF) of photon system is usually used as a quantum channel, showing disadvantages of low capacity and susceptibility to noise. In this paper, we present an efficient multi-hop quantum hyperentanglement swapping (HES) method based on hyperentanglement, which utilizes the entangled photos in polarization and spatial-mode DOFs to establish the hyperentangled multi-hop quantum channel. Taking long-distance hyperentanglement based quantum teleportation for example, we first describe a basic hop by hop HES scheme. Then, in order to reduce the end-to-end delay of this scheme, we propose a simultaneous HES (SHES) scheme, in which the intermediate quantum nodes perform hyperentangled Bell state measurements concurrently. On the basis of this scheme, we further put forward a hierarchical SHES (HSHES) scheme that can reduce the classical information cost. Theoretical analysis and simulation results show that the end-to-end delay of HSHES is similar to that of SHES, meanwhile, the classical information cost of HSHES is much lower than that of SHES, showing a better tradeoff between the two performance metrics. Compared with the traditional ES methods, the scheme proposed in this paper is conductive to meeting the requirements for long-distance hyperentanglement based quantum communication, which has positive significance for building more efficient quantum networks in the future.
The combination of quantum communication technology and wireless networks brings a flexible and secure communication method, which adapts to a more complex network environment. In this paper, a new multi-hop teleportation scheme is investigated for transferring an unknown qutrit state between distant parties. The intermediate nodes are introduced and linked with each other via partially entangled Greenberger-Horne-Zeilinger (GHZ) states as quantum channels. In this multi-hop teleportation protocol, the source node and all the intermediate nodes can perform the entanglement measurement and transmit the measurement results simultaneously. Furthermore, we find the relationship between the measurement results and the receiver’s state, which is given as the matrix form. Compared with previous protocols for multi-hop transmission, our scheme can reduce the transmission delay and save the transmission overhead.
Abstract Quantum teleportation is one of the key technologies enabling long-distance quantum communication. However, the decoherence in realistic channels makes it difficult to maintain maximal entanglement. Furthermore, the capability to perform high-dimensional unitary operations poses a significant challenge, as not all the nodes in the quantum network possess this ability. Meanwhile, low transmission rates also hinder the development of quantum networks. We propose a flexible multi-hop non-destructive teleportation via non-maximally entangled GHZ channels, where the network is partitioned into upstream and downstream segments. Direct entanglement channels are established via simultaneous entanglement swapping and multi-level hierarchical swapping. Channel modulation is performed by the selected intermediate parties with high-dimensional operational capabilities and auxiliary particles. In this framework, the sender and the receiver are responsible only for information transmission, while other intermediate nodes perform only basic operations, such as Bell-state and Hadamard ( H ) measurements. In this scheme, any intermediate node possesses high-dimensional unitary operation capability, making the teleportation process flexible in terms of node deployment and operational responsibility, thereby reducing the requirements for the communication terminals.