Quantum Teleportation Protocol Research Articles

An efficient asymmetric bidirectional quantum teleportation protocol and the analysis of its performance over noisy environments

An efficient asymmetric bidirectional quantum teleportation protocol and the analysis of its performance over noisy environments

Linear Optical Protocol for Asymmetric Bidirectional Quantum Teleportation

Linear Optical Protocol for Asymmetric Bidirectional Quantum Teleportation

Overcoming noise in quantum teleportation with multipartite hybrid entanglement.

Quantum entanglement and decoherence are the two counterforces of many quantum technologies and protocols. For example, while quantum teleportation is fueled by a pair of maximally entangled resource qubits, it is vulnerable to decoherence. Here, we propose an efficient quantum teleportation protocol in the presence of pure decoherence and without entangled resource qubits entering the Bell-state measurement. Instead, we use multipartite hybrid entanglement between the auxiliary qubits and their local environments within the open-quantum system context. With a hybrid-entangled initial state, it is the decoherence that allows us to achieve high fidelities. We demonstrate our protocol in an all-optical experiment.

Effects of Quantum Noise on Teleportation of an Arbitrary Two-Qubi t State via a Five-Particle Brown State

Abstract We propose an innovative protocol for quantum teleportation (QT) which employs the Brown state as the quantum channel. Our study focuses on the teleportation of a single unknown two-qubit state via a Brown state channel in an ideal environment. To validate the effectiveness of our proposed scheme, we conduct experiments using the quantum circuit simulator Quirk. Furthermore, we investigate the impact of four noisy channels, namely the phase damping noise, the bit-flip noise, the amplitude damping noise and the phase-flip noise. Notably, we employ Monte Carlo simulation to elucidate the fidelity density under various noise parameters. Our analysis demonstrates that the fidelity of the protocol in a noisy environment is influenced significantly by the amplitude of the initial state and the noise factor.

Satellite-based entanglement distribution and quantum teleportation with continuous variables

Advances in satellite quantum communications aim at reshaping the global telecommunication network by increasing the security of the transferred information. Here, we study the effects of atmospheric turbulence in continuous-variable entanglement distribution and quantum teleportation in the optical regime between a ground station and a satellite. More specifically, we study the degradation of entanglement due to various error sources in the distribution, namely, diffraction, atmospheric attenuation, turbulence, and detector inefficiency, in both downlink and uplink scenarios. As the fidelity of a quantum teleportation protocol using these distributed entangled resources is not sufficient, we include an intermediate station for either state generation, or beam refocusing, in order to reduce the effects of atmospheric turbulence and diffraction, respectively. The results show the feasibility of free-space entanglement distribution and quantum teleportation in downlink paths up to the LEO region, but also in uplink paths with the help of the intermediate station. Finally, we complete the study with microwave-optical comparison in bad weather situations, and with the study of horizontal paths in ground-to-ground and inter-satellite quantum communication.

Continuous variable quantum teleportation network with star topology

Quantum network allows communication among more than two users with quantum teleportation and high quantum fidelity enabled by non-classical resources. As one of the most versatile architectures, all users are connected mediated by the central station in the star topology network, leading to the realization of the information interconnection and interoperability. In this work, we experimentally demonstrate a 4-branch continuous variable (CV) quantum teleportation network with star topology by employing entangled sideband modes from one squeezed state of light. Here, multiple pairs of entangled sideband modes are distributed on demand to central station and four nodes, respectively. Each node linked to the network has its own communication channel with the central station, where the deterministic CV quantum teleportation protocol is implemented with the fidelities above 0.830.

Toy gravizap for black hole redemption

In this note we discuss a topological realization of the quantum teleportation protocol. Such a realization facilitates keeping track of the evolution of quantum correlations in the system. It is then suggested, that an implementation of a similar protocol can serve as a toy model of a process of information transfer between causally disconnected regions, such as the one that should take place in a unitary evolution of a quantum black hole. Hawking quanta provide the necessary entangled pairs for the teleportation channel, and the same interaction mechanism that creates the Hawking pairs, destroys the entanglement at the late stages of the evolution. Different steps of the teleportation protocol are characterized by the entropies associated with the disconnected regions, and one can introduce an analog of the Page curve for the entropy of the Hawking radiation. Some regions of the “black hole” interior appear to actually encode the information of the exterior, so it is natural to identify them with the “islands” of the semiclassical gravity analysis.

Protecting quantum correlations of negative quantum states using weak measurement under non-Markovian noise

The weak measurement (WM) and quantum measurement reversal (QMR) are crucial in protecting the collapse of quantum states. The idea of WM and QMR has recently been used to protect and enhance quantum correlations and universal quantum teleportation (UQT) protocols. Here, we study the quantum correlations, maximal fidelity, and fidelity deviation of the two-qubit negative quantum states developed using discrete Wigner functions with(without) WM and QMR. To take into account the effect of a noisy environment, we evolve the states via non-Markovian amplitude damping and random telegraph noise quantum channels. To benchmark the performance of negative quantum states, we calculate their success probability. We compare our results with the two-qubit maximally entangled Bell state. Interestingly, we observe that some negative quantum states perform better with WM and QMR than the Bell state for different cases under evolution via noisy quantum channels.

Quantum state transfer through system-environment correlation

Quantum state transfer protocol based on system-environment correlation is studied. Different from that in protocol of quantum teleportation, in the present transfer protocol, parties do not share entangled state initially. The state factors are transmitted among parties through their common memory-environment. Explicitly, with the generation of system-environment correlation, state factors parameterized on the probe system can be transmitted to the environment by performing proper projective measurement on the probe system. Then after knowing the results of former measurements, other parties can estimate the state factors by preparing proper detectors that evolve with the memory environment for a proper period of time. In this regard, quantum state is transmitted among different parties through system-environment correlation. Since quantum decoherence appears along with the generation of system-environment correlation, using the present transfer protocol, one can transmit quantum state even after the characteristic time of quantum decoherence.

Quantum teleportation and dynamics of quantum coherence and metrological non-classical correlations for open two-qubit systems

We investigate the dynamics of non-classical correlations and quantum coherence in open quantum systems by employing metrics like local quantum Fisher information, local quantum uncertainty, and quantum Jensen-Shannon divergence. Our focus here is on a system of two qubits in two distinct physical situations: the first one when the two qubits are coupled to a cavity field whether the system is closed or open, while the second consists of two qubits immersed in dephasing reservoirs. Our study places significant emphasis on how the evolution of these quantum criterion is influenced by the initial state’s purity (whether pure or mixed) and the nature of the environment (whether Markovian or non-Markovian). We observe that a decrease in the initial state’s purity corresponds to a reduction in both quantum correlations and quantum coherence, whereas higher purity enhances these quantumness. Furthermore, we establish a quantum teleportation strategy based on the two different physical scenarios. In this approach, the resulting state of the two qubits functions as a quantum channel integrated into a quantum teleportation protocol. We also analyze how the purity of the initial state and the Markovian or non-Markovian regimes impact the quantum teleportation process.

Symmetric bidirectional quantum teleportation via eight-qubit cluster state

This paper proposes a symmetric bidirectional quantum teleportation protocol through an eight-qubit cluster state as a quantum channel to achieve GHZ state interchange between two parties. Alice and Bob must first perform two CNOT gate operations on the unknown GHZ state to be sent in our scheme. Next, they need to complete the Bell state measurements and the corresponding unitary operations to obtain the corresponding GHZ state. Our protocol has lower operational complexity and higher inherent efficiency compared to other protocols. In addition, we have simulated the quantum circuit on the IBM qasm simulator to verify the feasibility of the protocol.

Hierarchical Controlled Hybrid Quantum Communication Based on Six-Qubit Entangled States in IoT.

The rapid development and extensive application of the Internet of Things (IoT) have brought new challenges and opportunities to the field of communication. By integrating quantum secure communication with the IoT, we can provide a higher level of security and privacy protection to counteract security threats in the IoT. In this paper, a hybrid quantum communication scheme using six-qubit entangled states as a channel is proposed for specific IoT application scenarios. This scheme achieves hierarchical control of communication protocols on a single quantum channel. In the proposed scheme, device A transmits data to device B through quantum teleportation, while device B issues control commands to device A through remote quantum state preparation technology. These two tasks are controlled by control nodes C and D, respectively. The transmission of information from device A to device B is a relatively less important task, which can be solely controlled by control node C. On the other hand, issuing control commands from device B to device A is a more crucial task requiring joint control from control nodes C and D. This paper describes the proposed scheme and conducts simulation experiments using IBM's Qiskit Aer quantum computing simulator. The results demonstrate that the fidelity of the quantum teleportation protocol (QTP) and the remote state preparation protocol (RSP) reach an impressive value of 0.999, fully validating the scheme's feasibility. Furthermore, the factors affecting the fidelity of the hybrid communication protocol in an IoT environment with specific quantum noise are analyzed. By combining the security of quantum communication with the application scenarios of the IoT, this paper presents a new possibility for IoT communication.

Free-Space Quantum Teleportation with Orbital Angular Momentum Multiplexed Continuous Variable Entanglement

Quantum teleportation is one of the fundamental primitives of quantum cryptography. In order to achieve a wider range of high-capacity information transfer, we propose a free-space quantum teleportation (QT) protocol with orbital angular momentum (OAM) multiplexed continuous variable (CV) entangled states. The preparation of the entangled states is accomplished by the spontaneous four-wave mixing (SFWM) process occurring in a hot 85Rb vapor cell, and the mode selection for the Bell-state measurement is achieved by employing the balanced homodyne detection technique. The fidelity of teleporting EPR entangled states carrying different topological charges via a Kolmogorov-type atmospheric turbulence channel is derived, and the superiority of enhancing the system channel capacity via OAM multiplexing is demonstrated. Our work provides a feasible scheme to implement high-capacity quantum communication in atmospheric environments.

Asymmetric tridirectional quantum teleportation using seven-qubit cluster states

This paper proposes an asymmetric tridirectional quantum teleportation (TQT) protocol that uses a seven-qubit cluster states as the quantum channels of each party. In this scheme, any one of the three participants can send their arbitrarily entangled states to the other two concurrently. The tridirectional functionality shows that all three users can act as sender and receiver simultaneously. Based on the mathematical modeling of the scheme, the quantum circuit and the appropriate quantum channel is proposed. For examination and implementation, the proposed scheme and circuit were simulated and validated using IBM quantum experience platform, QASM_simulator and Qiskit library.

Bidirectional hierarchical quantum teleportation based on an eight-qubit entangled state

This article proposes an asymmetric bidirectional hierarchical quantum teleportation protocol, which is based on a quantum channel composed of a maximum of eight-qubit entangled state. With this method, Alice can transmit an unknown single-qubit state to Bob, meanwhile, Bob can transmit an arbitrary unknown two-qubit quantum state to Alice. As a sender with high authority, Bob can send any unknown two-qubit quantum state to Alice only under the sole control of the controller Charlie; Alice, as a sender with low-level permissions, if Bob intends to receive the unknown single-qubit quantum state sent by Alice, he must get the permission and assistance of Charlie and David to complete the communication.

Connectomes and properties of quantum entanglement

Topological quantum field theories (TQFT) encode properties of quantum states in the topological features of abstract manifolds. One can use the topological avatars of quantum states to develop intuition about different concepts and phenomena of quantum mechanics. In this paper we focus on the class of simplest topologies provided by a specific TQFT and investigate what the corresponding states teach us about entanglement. These “planar connectome” states are defined by graphs of simplest topology for a given adjacency matrix. In the case of bipartite systems the connectomes classify different types of entanglement matching the classification of stochastic local operations and classical communication (SLOCC). The topological realization makes explicit the nature of entanglement as a resource and makes apparent a number of its properties, including monogamy and characteristic inequalities for the entanglement entropy. It also provides tools and hints to engineer new measures of entanglement and other applications. Here the approach is used to construct purely topological versions of the dense coding and quantum teleportation protocols, giving diagrammatic interpretation of the role of entanglement in quantum computation and communication. Finally, the topological concepts of entanglement and quantum teleportation are employed in a simple model of information retrieval from a causally disconnected region, similar to the interior of an evaporating black hole.

Detecting quantum critical points at finite temperature via quantum teleportation

We show that the quantum teleportation protocol is a powerful tool to study quantum phase transitions (QPTs) at finite temperatures. We consider a pair of spins from an infinite spin-1/2 chain (XXZ model) in equilibrium with a reservoir at temperature T as the resource used by Alice and Bob to implement the teleportation protocol. We show that the efficiency of this pair of spins to teleport a qubit is drastically affected after we cross a quantum critical point (QCP), even for high values of T. Also, we show that the present tool is as sharp as quantum discord (QD) to spotlight a QCP, where QD is the best finite T QCP detector known to date. Contrary to QD, however, we show that the present tool is easier to compute theoretically and has a direct experimental and operational meaning.

Non-ambiguous and simplified quantum teleportation protocol

In this study, a new version of the quantum teleportation protocol is presented, which does not require a Bell state measurement (BSM) module on the sender side (Alice), a unitary transform to reconstruct the teleported state on the receiver side (Bob), neither a disambiguation process through two classic bits that travel through a classic disambiguation channel located between sender and receiver. The corresponding theoretical deduction of the protocol, as well as the experimental verification of its operation for several examples of qubits through implementation on an optical table, complete the present study. Both the theoretical and experimental outcomes show a marked superiority in the performance of the new protocol over the original version, with more simplicity and lower implementation costs, and identical fidelity in its most complete version.

Exploring postselection-induced quantum phenomena with time-bidirectional state formalism

Here we present the time-bidirectional state formalism (TBSF) unifying in a general manner the standard quantum mechanical formalism with no postselection and the time-symmetrized two-state (density) vector formalism, which deals with postselected states. In the proposed approach, a quantum particle's state, called a time-bidirectional state, is equivalent to a joined state of two particles propagating in opposite time directions. For a general time-bidirectional state, we derive outcome probabilities of generalized measurements, as well as mean and weak values of Hermitian observables. We also show how the obtained expressions reduce to known ones in the special cases of no postselection and generalized two-state (density) vectors. Then we develop tomography protocols based on mutually unbiased bases and a symmetric informationally complete positive operator-valued measure, allowing experimental reconstruction of an unknown single qubit time-bidirectional state. Finally, we employ the developed techniques for tracking of a qubit's time-reversal journey in a quantum teleportation protocol realized with a cloud-accessible noisy superconducting quantum processor. The obtained results justify an existence of a postselection-induced qubit's proper time-arrow, which is different from the time-arrow of a classical observer, and demonstrate capabilities of the TBSF for exploring quantum phenomena brought forth by a postselection in the presence of noise.

Rough Entanglement: Not Enough Fourier

AbstractThis work presents a new form of entanglement known as rough entanglement. It is based on the quantum Fourier transform (QFT) and is an alternative to those used in quantum information processing for generating maximally and nonmaximally entangled states. The roughly entangled pairs are used in the quantum teleportation protocol, where, the performance achieved in the reconstruction of the teleported state is evaluated. The aforementioned teleportation is implemented on a simulator and a 5‐qubit physical machine from the IBM Q Experience inventory. Emphasis is placed on the teleportation of computational basis states (CBS) commonly used in quantum key distribution protocols. Finally, in previous works, it is shown that to generate Bell states the intervention of two QFT blocks is required, while the rough version requires only one. The lack of a second layer or QFT block in its constitution gives the name to this new type of entanglement.