Quantum Teleportation Scheme Research Articles

An Efficient Scheme of Quantum Wireless Multi-hop Communication using Coefficient Matrix

By defining the coefficient matrix, a new quantum teleportation scheme in quantum wireless multi-hop network is proposed. With the help of intermediate nodes, an unknown qubit state can be teleported between two distant nodes which do not share entanglement in advance. Arbitrary Bell pairs and entanglement swapping are utilized for establishing quantum channel among intermediate nodes. Using collapsed matrix, the initial quantum state can be perfectly recovered at the destination.

Simultaneous Quantum Transmission and Teleportation of Unknown Photons Using Intra- and Inter-particle Entanglement Controlled-NOT Gates via Cross-Kerr Nonlinearity and P-Homodyne Measurements

We propose an arbitrary controlled-unitary (CU) gate and a simultaneous quantum transmission and teleportation (SQTTP) scheme. The proposed CU gate utilizes photons with cross-Kerr nonlinearities (XKNLs), coherent superposition states (CSSs) and P-homodyne detectors and consists of the consecutive operation of a controlled-path (C-path) gate and a gathering-path (G-path) gate It is almost deterministic and feasible with current technology when strong CSSs and weak XKNLs are employed. Compared with the existing multi-qubit or controlled gates, which utilize XKNLs, coherent states, and X-homodyne detectors, the proposed CU gate can increase the feasibility of experimental realization, and enhance the robustness against the decoherence effect. Based on the CU gate, we present a SQTTP scheme that simultaneously transmits and teleports two unknown states of photons between two parties (Alice and Bob) using path-polarization intra-particle hybrid entanglement (IRHE) by transferring only a single photon. Consequently, it is possible to experimentally implement SQTTP with a certain success probability using the proposed CU gate.

Fidelity recovery scheme for quantum teleportation in amplitude damping channel

During the course of quantum teleportation in amplitude damping channel, the quantum Bell entanglement state will suffer a de-coherence, which will lead to the quality decrease of quantum teleportation, or even communication failure. To overcome this influence, we propose a method to compensate for the de-coherence of Bell entanglement state. Based on the parameter estimation of the amplitude damping channel, the compensation is divided into two steps. The first step (called pre-compensation) is carried out before the occurrence of de-coherence; the second step (called match-compensation) is carried out after the quantum entanglement state has experienced the de-coherence in the amplitude damping channel. The former is done at the EPR source device, while the latter is done at the quantum user device. The parameters of pre-compensation and match-compensation are determined by the amplitude damping coefficient. The quantum teleportation is carried out after the entanglement compensation. We will give the theoretical derivation and performance analysis of this method. Compared with the method that has no compensation and the method that the compensation is only done after de-coherence, the method given in this paper has a higher quantum teleportation fidelity which is close to 1, when the compensation parameter is adjusted accurately. Our method shows an effective influence on the teleportation quality decrease due to the entanglement de-coherence.

High fidelity quantum teleportation assistance with quantum neural network

In this paper, a high fidelity scheme of quantum teleportation based on quantum neural network (QNN) is proposed. The QNN is composed of multi-bit control-not gates. The quantum teleportation of a qubit state via two-qubit entangled channels is investigated by solving the master equation in Lindblad operators with a noisy environment. To ensure the security of quantum teleportation, the indirect training of QNN is employed. Only 10% of teleported information is extracted for the training of QNN parameters. Then the outputs are corrected by the other QNN at Bob's side. We build a random series of numbers ranged in [0, π] as inputs and simulate the properties of our teleportation scheme. The results show that the fidelity of quantum teleportation system is significantly improved to approach 1 by the error-correction of QNN. It illustrates that the distortion can be eliminated perfectly and the high fidelity of quantum teleportation could be implemented.

Quantum teleportation of spin coherent states: beyond continuous variables teleportation

We introduce a quantum teleportation scheme that transfers a spin coherent state between two locations using entanglement. In the scheme an unknown spin coherent state lying on the equator of the Bloch sphere, such as realized in a coherent two-component Bose–Einstein condensate, is teleported onto a distant spin coherent state using only elementary operations and measurements. The scheme works in the regime beyond the standard continuous variables approximation based on the Holstein–Primakoff transformation. We analyze the error of the protocol with the number of particles N in the spin coherent state under decoherence and find that it scales favorably with N. The simplicity of the operations involved and the robustness under decoherence should make the protocol suitable under realistic experimental conditions.

Continuous-variable versus hybrid schemes for quantum teleportation of Gaussian states

In this paper, we examine and compare two fundamentally different teleportation schemes; the well-known continuous variable scheme by Vaidman, Braunstein and Kimble (VBK), and a recently proposed hybrid scheme by Andersen and Ralph (AR). We analyze the teleportation of ensembles of arbitrary pure single-mode Gaussian states using these schemes and see how they fare against the optimal measure-and-prepare strategies -- the benchmarks. In the VBK case, we allow for non-unit gain tuning and consider a class of possibly non-Gaussian resources in order to optimize performance. The results suggest that the AR scheme may likely be a more suitable candidate for beating the benchmarks in the teleportation of squeezing, capable of achieving this for moderate resources in comparison to the VBK scheme. Moreover, our quantification of resources, whereby different protocols are compared at fixed values of the entanglement entropy or the mean energy of the resource states, brings into question any advantage due to non-Gaussianity for quantum teleportation of Gaussian states.

Perfect Teleportation of an Arbitrary Two-Qubit State via GHZ-Like States

We propose a novel and efficient scheme for quantum teleportation of an arbitrary two-qubit state via GHZ-like states. In this scheme, the sender Alice performs two three-qubit von-Neumann projective measurements on the qubits, the receiver Bob can reconstruct the original state by making appropriate unitary transformations. This quantum teleportation scheme is perfect, i.e. the success probability can reach 1.

Identity authentication by entanglement swapping in controlled quantum teleportation

Controlled quantum teleportation (CQT) is to realise communication between a sender Alice and a receiver Bob to cooperate with a controller Charlie. It can send any quantum state α|0〉 + β|1〉 successfully by this quantum communication system. However, its drawback is that Alice can not confirm Charlie’s and Bob’s identities. In this paper, we design two identity authentication schemes IA_C and IA_B based on entanglement swapping to make identification confirmation for Charlie and Bob, and use decoy states to check outside eavesdropping. Alice confirms the identity of Charlie by using two Bell states entanglement swapping. Moreover, the identity confirmation of Bob by Alice with the help of Charlie is to use three Bell states entanglement swapping. The scheme can effectively prevent forgery identity attack to ensure the security of quantum teleportation. We also propose an improved controlled quantum teleportation (ICQT) scheme with decoy states to ensure the security of quantum channel.

Bidirectional Controlled Quantum Teleportation by Using Five-Qubit Entangled State

We propose a scheme for bidirectional controlled quantum teleportation by using a genuine five-qubit entangled state. In our scheme, Alice may transmit an arbitrary single qubit state of qubit A to Bob and at the same time, Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie.

Displacement gain dependent fidelity in quantum teleportation using entangled two-mode squeezed light

We study a scheme for quantum teleportation of a single-mode squeezed coherent state using entangled two-mode squeezed vacuum. We establish the analytic expression of displacement gain dependent fidelity in terms of the squeezing coherent parameter \(r\) and quantum channel parameter \(p\). The dependence of the optimum displacement gain for teleporting a squeezed coherent state upon the EPR entanglement is discussed. It shows that the fidelity of teleportation can be improved by tuning the displacement gain. We find that the fidelity increases with the increase of EPR parameter, while it decreases with the increase of the squeezing coherent parameter of the signal. We get infinite squeezing as a resource is required for an ideal and perfect teleportation of unknown input states. We show that the nonclassical properties of an unknown state to be teleported can be preserved in the teleportation.

A Teleportation with Two Quantum Channels

Recently a quantum teleportation scheme has been analyzed by Wangner et al. (J. Opt. Soc. Am. B 27:A73–A80, 2010) which is based on spatially and temporarily resolved collective spontaneous emission. We study a similar model, which has the two atoms trapped in a resonant cavity instead of in the free vacuum space. It is found that the quantum channel experiences entanglement of sudden death (ESD), yet every time this channel can recover after an interval of time. Surprisingly, we demonstrate there exits another channel to assist the initial channel to complete the teleportation, and the fidelity can be well beyond the classical limit of 2/3, with the increase of dipole-dipole interaction.

Several teleportation schemes of an arbitrary unknown multi-particle state via different quantum channels

We first provide four new schemes for two-party quantum teleportation of an arbitrary unknown multi-particle state by using three-, four-, and five-particle states as the quantum channel, respectively. The successful probability and fidelity of the four schemes reach 1. In the first two schemes, the receiver can only apply one of the unitary transformations to reconstruct the original state, making it easier for these two schemes to be directly realized. In the third and fourth schemes, the sender can preform Bell-state measurements instead of multipartite entanglement measurements of the existing similar schemes, which makes real experiments more suitable. It is found that the last three schemes may become tripartite controlled teleportation schemes of teleporting an arbitrary multi-particle state after a simple modification. Finally, we present a new scheme for three-party sharing an arbitrary unknown multi-particle state. In this scheme, the sender first shares three three-particle GHZ states with two agents. After setting up the secure quantum channel, an arbitrary unknown multi-particle state can be perfectly teleported if the sender performs three Bell-state measurements, and either of two receivers operates an appropriate unitary transformation to obtain the original state with the help of other receiver's three single-particle measurements. The successful probability and fidelity of this scheme also reach 1. It is demonstrated that this scheme can be generalized easily to the case of sharing an arbitrary unknown multi-particle state among several agents.

Quantum Teleportation of the Two-Qubit Entangled State by Use of Four-Qubit Entangled State

In this article, a scheme for quantum teleportation of a two-qubit entangled state using four-qubit cluster state is discussed by use of cavity quantum electrodynamics (QED) involving the interaction of the atoms with the cavity. In this protocol, by using a one-dimensional maximally four-qubit cluster state as quantum channel, quantum information of an unknown state of two two-level particles is faithfully transmitted from a sender (Alice) to a remote receiver (Bob). According to the results measured by the Bob, as it is shown, the unknown two-particle entangled state can be teleported perfectly, and the successful possibilities and fidelities of the scheme can reach 1.0.

Scheme for Implementing Controlled Quantum Teleportation in QDS-Cavity System

In this article, we propose an experimental scheme for implementing quantum teleportation of tripartite GHZ-Like state under the control of the controller. Due to the entanglement produced by the interaction between quantum dots embedded in microcavities and a single photon, the controlled quantum teleportation scheme of tripartite GHZ-Like state encoded in the electron spins in quantum dots can be realized in terms of theory via the conditional Faraday rotation of the polarization of single photons, single photons detection, and electron spin orientation measurement. By choosing the appropriate Faraday rotation angle for the switchable microcavities, the success probability of controlled quantum teleportation can reach 1. The similar controlled quantum teleportation procedure discussed here can be generalized to the quantum teleportation of multipartite GHZ-Like state.

Perfect quantum teleportation and dense coding protocols via the 2N-qubit W state

In this paper, we investigate perfect quantum teleportation and dense coding by using an 2N-qubit W state channel. In the quantum teleportation scheme, an unknown N-qubit entangled state can be perfectly teleported. One ebit of entanglement and two bits of classical communication are consumed in the teleportation process, just like when using the Bell state channel. While N + 1 bits of classical information can be transmitted by only sending N particles in the dense coding protocol.

Increasing Success Probability of a Probabilistic Quantum Teleportation

The probabilistic quantum teleportation scheme [Phys. Lett. A 305 (2002) 12] is improved via two seemingly different methods (i.e., the usual ancilla method and the so-called Kraus method), respectively. The essence of the improvements is to fetch a part from the residues so that the success probability is accordingly increased. The two improved versions and a similar protocol proposed by Li et al. [Phys. Rev. A 61 (2000) 034301] are compared mutually and discussed. It is found that they are equally efficient and can reach the success probability threshold determined by the inherent entanglement of the quantum channel.

Scheme for teleportation of unknown single qubit state via continuous variables entangling channel

A new scheme for quantum teleportation of single quantum bit state with using continuous variables entangling channel is presented. In our scheme two entangled light fields are employed. An outstanding characteristic of this scheme is that one atomic state is transmitted directly to another atom without using the third atom as the mediate.

Transfer information remotely via noise entangled coherent channels

A simple scheme of quantum teleportation is introduced to investigate the possibility of remotely transfer unknown tripartite state by using a multipartite entangled coherent state. A theoretical technique is introduced to generate maximum entangled coherent states and a generalized teleportation protocol is introduced. The fidelity of the teleported state increases significantly when increasing the number of modes in the case of large noise, whereas it shows the opposite behavior in the case of small noise.

Quantum Teleportation and Quantum Information Splitting by Using a Genuinely Entangled Six-Qubit State

A new application of the genuinely entangled six-qubit state introduced recently by Tapiador et al. (J. Phys. A 42:415301, 2009) is investigated for the quantum teleportation of an arbitrary three-qubit state and for quantum information splitting (QIS) of an arbitrary two-qubit state. For QIS, we have shown that it can be completed perfectly with two distinct measurement methods. In our scheme, the joint Bell-state measurement and the joint multi-qubit measurement are needed. This quantum teleportation and QIS schemes are deterministic.

ENCRYPTION-BASED NETWORKING QUANTUM TELEPORTATION WITH TRIPLET GREENBERGER–HORNE–ZEILINGER STATES

An encryption-based networking quantum teleportation scheme is proposed for the secure quantum communication network based on the novel networking quantum key distribution (NQKD) with the Greenberger–Horne–Zeilinger (GHZ) state. The security is exactly guaranteed via the entanglement of the GHZ quantum system. In the process of quantum teleportation, the server Charlie prepares the GHZ states and the users exploit the four local unitary operations corresponding to the keys shared aforehand to encrypt/decrpt for the initial messages. One legal user can communicate with another on the network securely as they may perform a quantum privacy application on the encrypted quantum states transmitted in quantum channel. Its intrinsic efficiency is high as almost all the instances are useful and each GHZ state can carry two different encrypted single-qubit states. To reconstruct these transmitted messages, the users exploit Bell measurement and perform local operations with respect to the shared keys in NQKD, which will improve its security in a noise quantum channel.