scholarly journals EFFICIENT QUANTUM CIRCUITS FOR PERFECT AND CONTROLLED TELEPORTATION OF n-QUBIT NON-MAXIMALLY ENTANGLED STATES OF GENERALIZED BELL-TYPE

2011 ◽  
Vol 09 (supp01) ◽  
pp. 389-403 ◽  
Author(s):  
ANIRBAN PATHAK ◽  
ANINDITA BANERJEE
Keyword(s):  
Quantum Channel ◽  
Quantum Teleportation ◽  
Bell State ◽  
Ghz State ◽  
Quantum Circuits ◽  
Controlled Teleportation ◽  
Entangled State ◽  
Maximally Entangled State ◽  
Tripartite Entangled State ◽  
Maximally Entangled States

An efficient and economical scheme is proposed for the perfect quantum teleportation of n-qubit non-maximally entangled state of generalized Bell-type. A Bell state is used as the quantum channel in the proposed scheme. It is also shown that the controlled teleportation of this n-qubit state can be achieved by using a GHZ state or a GHZ-like state as quantum channel. The proposed schemes are economical because for the perfect and controlled teleportation of n-qubit non-maximally entangled state of generalized Bell-type, we only need a Bell state and a tripartite entangled state respectively. It is also established that there exists a family of 12 orthogonal tripartite GHZ-like states which can be used as quantum channel for controlled teleportation. The proposed protocols are critically compared with the existing protocols.

scholarly journals MAXIMALLY ENTANGLED STATES AND BELL'S INEQUALITY IN RELATIVISTIC REGIME

2009 ◽  
Vol 07 (01) ◽  
pp. 395-401 ◽  
Author(s):  
SHAHPOOR MORADI
Keyword(s):  
Ghz State ◽  
Entangled States ◽  
Entangled State ◽  
Maximally Entangled State ◽  
Expectation Value ◽  
Spin Observables ◽  
Chsh Inequality ◽  
Relativistic Regime ◽  
Maximal Violation ◽  
Maximally Entangled States

In this letter we show that in the relativistic regime, maximally entangled state of two spin-1/2 particles not only gives maximal violation of the Bell-CHSH inequality but also gives the largest violation attainable for any pairs of four spin observables that are noncommuting for both systems. Also, we extend our results to three spin-1/2 particles. We obtain the largest eigenvalue of Bell operator and show that this value is equal to the expectation value of Bell operator on GHZ state.

Asymmetric bidirectional quantum teleportation via six-qubit partially entangled state

2021 ◽  
pp. 2150208
Author(s):  
Jinwei Wang ◽  
Liping Huang
Keyword(s):  
Quantum Channel ◽  
Quantum Teleportation ◽  
Bell State ◽  
Qubit State ◽  
Entangled State ◽  
Controlled Quantum Teleportation ◽  
Single Qubit ◽  
Bidirectional Quantum Teleportation ◽  
Bell State Measurements ◽  
Partially Entangled State

In this paper, an asymmetric bidirectional controlled quantum teleportation via a six-qubit partially entangled state is given, in which Alice wants to transmit a two-qubit entangled state to Bob and Bob wants to transmit a single-qubit state to Alice on the same time. Although the six-qubit state as quantum channel is partially entangled, the teleportation is implemented deterministically. Furthermore, only Bell-state measurements, single-qubit measurements and some unitary operations are needed in the scheme.

PERFECT TELEPORTATION OF UNKNOWN QUDIT BY A d-LEVEL GHZ CHANNEL

2009 ◽  
Vol 07 (04) ◽  
pp. 755-770 ◽  
Author(s):  
YINXIANG LONG ◽  
DAOWEN QIU ◽  
DONGYANG LONG
Keyword(s):  
General Scheme ◽  
Bell State ◽  
Ghz State ◽  
Quantum States ◽  
Entangled State ◽  
Input State ◽  
Quantum Channels ◽  
Maximally Entangled State ◽  
Ghz States ◽  
Measurement Basis

In the past decades, various schemes of teleportation of quantum states through different types of quantum channels (a prior shared entangled state between the sender and the receiver), e.g. EPR pairs, generalized Bell states, qubit GHZ states, standard W states and its variations, genuine multiqubit entanglement states, etc., have been developed. Recently, three-qutrit quantum states and two-qudit quantum states have also been considered as quantum channels for teleportation. In this paper, we investigate the teleportation of an unknown qudit using a d level GHZ state, i.e. a three-qudit maximally entangled state, as quantum channel. We design a general scheme of faithful teleportation of an unknown qudit using a d-level GHZ state shared between the sender and the receiver, or among the sender, the receiver and the controller; an unknown two-qudit of Schmidt form using a d level GHZ state shared between the sender and the receiver; as well as an unknown arbitrary two-qudit using two shared d level GHZ states between the sender, the receiver and the controller, or using one shared d level GHZ state and one shared generalized Bell state. We obtain the general formulas of Alice's measurement basis, Charlie's measurement basis and Bob's unitary operations to recover the input state of Alice. It is intuitionistic to generalize the protocols of teleporting an arbitrary two-qudit state to teleporting an arbitrary n-qudit state.

Deterministic bidirectional quantum-controlled teleportation with six-qubit maximally entangled state

2019 ◽  
Vol 34 (35) ◽  
pp. 1950290 ◽  
Author(s):  
Wanbin Zhang
Keyword(s):  
Quantum Channel ◽  
Controlled Teleportation ◽  
Entangled State ◽  
Quantum Network ◽  
Maximally Entangled State ◽  
Bidirectional Quantum Controlled Teleportation ◽  
The Given

Each of three nodes in a quantum network has two qubits. The total six qubits are in a maximally entangled state [Helwig et al., Phys. Rev. A 86, 052335 (2012)]. Using such an entangled state as quantum channel, we put forward three deterministic bidirectional quantum-controlled teleportation (BQCT) schemes. To be specific, BQCT can be realized between any two nodes in a deterministic manner with another as the control. Alternatively, the BQCT capacity of such state in the given qubit distribution is thus essentially revealed by virtue of the schemes.

Deterministic quantum cyclic controlled teleportation of arbitrary multi-qubit states using multi-qubit partially entangled channel

2020 ◽  
Vol 35 (25) ◽  
pp. 2050204
Author(s):  
Shiya Sun ◽  
Huisheng Zhang
Keyword(s):  
Communication Networks ◽  
Quantum Channel ◽  
Success Probability ◽  
Bell State ◽  
Qubit State ◽  
Controlled Teleportation ◽  
Entangled State ◽  
Single Qubit ◽  
Qubit States ◽  
Partially Entangled Channel

In this paper, we present a deterministic four-party quantum cyclic controlled teleportation (QCYCT) scheme, by using a multi-qubit partially entangled state as the quantum channel. In this scheme, Alice can teleport an arbitrary [Formula: see text]-qubit state to Bob, Bob can teleport an arbitrary [Formula: see text]-qubit state to Charlie and Charlie can teleport an arbitrary [Formula: see text]-qubit state to Alice under the control of the supervisor David. We utilize rotation gate, Hadamard gates and controlled-NOT (CNOT) gates to construct the multi-qubit partially entangled channel. Only Bell-state measurements, single-qubit von-Neumann measurement and proper unitary operations are required in this scheme, which can be realized in practice easily based on the present quantum experiment technologies. The direction of cyclic controlled teleportation of arbitrary multi-qubit states can also be changed by altering the quantum channel. Analysis demonstrates that the success probability of the proposed scheme can still reach 100% although the quantum channel is non-maximally entangled. Furthermore, the proposed four-party scheme can be generalized into the case involving [Formula: see text] correspondents, which is more suitable for quantum communication networks. We also calculate the intrinsic efficiency and discuss the security of the proposed scheme. Compared with the existing QCYCT schemes which realized cyclic controlled teleportation of arbitrary single-qubit states, specific two-qubit and three-qubit states, the proposed scheme is of general significance.

Probabilistic Teleportation via a Partially Entangled GHZ State being Known by only the Sender

2014 ◽  
Vol 590 ◽  
pp. 799-802
Author(s):  
Li Xin Xia ◽  
Run Qin Liu ◽  
Wei Zheng
Keyword(s):  
Quantum Teleportation ◽  
Ghz State ◽  
Entangled State ◽  
Maximally Entangled State ◽  
Generalized Measurement ◽  
Probabilistic Teleportation

In some typical schemes, the receivers must know the information of a non-maximally entangled state for quantum teleportation. In this paper, using a generalized measurement, we propose a scheme of probabilistic teleportation via a quantum GHZ-entangled state, which is known by only the sender.

Four-agent bidirectional quantum controlled teleportation via quantum entanglement swapping

2021 ◽  
pp. 2150073
Author(s):  
Wanbin Zhang ◽  
Baosheng Li
Keyword(s):  
Quantum Entanglement ◽  
Quantum Channel ◽  
Entanglement Swapping ◽  
Controlled Teleportation ◽  
Entangled State ◽  
Long Distance ◽  
Maximally Entangled State ◽  
Distance Communication ◽  
Bidirectional Quantum Controlled Teleportation ◽  
The Given

A total of seven qubits are in a maximally entangled state. Using such an entangled state as quantum channel is based on the construction requirements of quantum long-distance communication [Pan et al., Nature 488, 185 (2012)]. Multi-party quantum channel (QC) should be studied. We put forward three deterministic bidirectional quantum controlled teleportation (BQCT) schemes. To be specific, BQCT can be realized between any two parties in a deterministic manner with another as the control. Alternatively, the BQCT capacity of such state in the given qubit distribution is thus essentially revealed by virtue of the schemes.

scholarly journals Optimal teleportation via noisy quantum channels without additional qubit resources

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dong-Gil Im ◽  
Chung-Hyun Lee ◽  
Yosep Kim ◽  
Hyunchul Nha ◽  
M. S. Kim ◽  
...  
Keyword(s):  
Quantum Computing ◽  
Quantum Teleportation ◽  
Quantum Communication ◽  
Quantum Noise ◽  
Single Copy ◽  
Entangled State ◽  
Quantum Network ◽  
Quantum Channels ◽  
Maximally Entangled State ◽  
Near Term

AbstractQuantum teleportation exemplifies how the transmission of quantum information starkly differs from that of classical information and serves as a key protocol for quantum communication and quantum computing. While an ideal teleportation protocol requires noiseless quantum channels to share a pure maximally entangled state, the reality is that shared entanglement is often severely degraded due to various decoherence mechanisms. Although the quantum noise induced by the decoherence is indeed a major obstacle to realizing a near-term quantum network or processor with a limited number of qubits, the methodologies considered thus far to address this issue are resource-intensive. Here, we demonstrate a protocol that allows optimal quantum teleportation via noisy quantum channels without additional qubit resources. By analyzing teleportation in the framework of generalized quantum measurement, we optimize the teleportation protocol for noisy quantum channels. In particular, we experimentally demonstrate that our protocol enables to teleport an unknown qubit even via a single copy of an entangled state under strong decoherence that would otherwise preclude any quantum operation. Our work provides a useful methodology for practically coping with decoherence with a limited number of qubits and paves the way for realizing noisy intermediate-scale quantum computing and quantum communication.

Symmetric and asymmetric cyclic controlled quantum teleportation via nine-qubit entangled state

2021 ◽  
pp. 2150249
Author(s):  
Vikram Verma
Keyword(s):  
Quantum Channel ◽  
Quantum Teleportation ◽  
Quantum States ◽  
Entangled State ◽  
Controlled Quantum Teleportation ◽  
Intrinsic Efficiency ◽  
Qubit States ◽  
Generalized Scheme

In this paper, by utilizing a nine-qubit entangled state as a quantum channel, we propose new schemes for symmetric and asymmetric cyclic controlled quantum teleportation (CYCQT). In our proposed schemes, four participants Alice, Bob, Charlie and David teleport their unknown quantum states cyclically among themselves with the help of a controller Eve. No participants can reconstruct the original states sent from the respective senders without the permission of the controller. Also, by considering same nine-qubit entangled state as a quantum channel, we propose a generalized scheme for CYCQT of multi-qubit states. In contrast to the previous CYCQT schemes involving three communicators and a controller, there are four communicators and a controller in the proposed schemes. Also, compared with previous CYCQT schemes, our proposed CYCQT schemes require less consumption of quantum resource and the intrinsic efficiency of the generalized scheme increases with the increase of number of qubits in the information states.

scholarly journals Probabilistic Resumable Quantum Teleportation of a Two-Qubit Entangled State

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 352 ◽  
Author(s):  
Zhan-Yun Wang ◽  
Yi-Tao Gou ◽  
Jin-Xing Hou ◽  
Li-Ke Cao ◽  
Xiao-Hui Wang
Keyword(s):  
Quantum Channel ◽  
Quantum Teleportation ◽  
The State ◽  
Entangled States ◽  
Entangled State ◽  
Quantum Channels ◽  
Unknown State ◽  
Optimal Probability

We explicitly present a generalized quantum teleportation of a two-qubit entangled state protocol, which uses two pairs of partially entangled particles as quantum channel. We verify that the optimal probability of successful teleportation is determined by the smallest superposition coefficient of these partially entangled particles. However, the two-qubit entangled state to be teleported will be destroyed if teleportation fails. To solve this problem, we show a more sophisticated probabilistic resumable quantum teleportation scheme of a two-qubit entangled state, where the state to be teleported can be recovered by the sender when teleportation fails. Thus the information of the unknown state is retained during the process. Accordingly, we can repeat the teleportion process as many times as one has available quantum channels. Therefore, the quantum channels with weak entanglement can also be used to teleport unknown two-qubit entangled states successfully with a high number of repetitions, and for channels with strong entanglement only a small number of repetitions are required to guarantee successful teleportation.

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