Four-particle Entangled State Research Articles

Authenticated quantum dialogue protocol based on four-particle entangled states

Many protocols of quantum dialogue are based on the assumption that the user is legitimate. In fact, the assumption is ideal. Therefore, it is necessary to identify whether the user is legitimate or not. In this paper, by adding identity authentication, a quantum dialogue protocol is proposed based on four-particle entangled states. For preparing the entangled state, we first give the description of the preparation process and draw the diagram of the prepared quantum circuit. Next, the nonlocal correlation properties of the entangled state are investigated. By associating identity authentication with channel security detection, the consumption of quantum resources is reduced to a certain extent. Furthermore, a random number r and a one-way hash function are added to increase the security of the protocol. In the end, compared with other protocols, our protocol has an improvement in efficiency.

A Controller-Independent Quantum Dialogue Protocol with Four-Particle States

Controller-independent quantum dialogue (CIQD) is a significant topic in the research of quantum secure direct communication (QSDC). In this paper, we propose a new CIQD protocol with a special kind of four-particle entangled states. From our security analysis, it can be seen that the information leakage which is a serious problem in many CIQD protocols will be prevented in our protocol. Moreover, the presented protocol can resist many existing attacks, including intercept-and-resend attack, entangle-and-measure attack, fake entangled particles attack.

Secure simultaneous dense coding using $$\chi $$ χ -type entangled state

A violation of a Bell inequality can formally be expressed as a witness for quantum nonlocality. A new four-qubit Bell inequality is optimally violated by $$\chi $$ -type entangled state, but not by four-qubit GHZ, W and cluster state. Hence, $$\chi $$ -type entangled state is a good candidate to implement simultaneous dense coding. In this paper, we propose a simultaneous dense coding protocol with genuine four-particle entangled state, $$\chi $$ -type entangled state, in which two receivers can simultaneously obtain their respective classical information sent by a sender. The double controlled-NOT operator, which is used as the locking operator, play a crucial role in our protocol. The security of simultaneous dense coding is analyzed against the intercept-resend attack. The preparation of $$\chi $$ -type entangled state has been studied in various physics systems, and it has been experimentally generated with nearly deterministic scheme and high generation rate. Thus, our protocol is feasible with the current experimental technology.

Intercept-Resend-Measure Attack Towards Quantum Private Comparison Protocol Using Genuine Four-Particle Entangled States and its Improvement

Recently, Jia et al. proposed the quantum private comparison protocol with the genuine four-particle entangled states (Jia et al., Int. J. Theor. Phys. 51(4), 1187–1194 (2012)). Jia et al. claimed that in this protocol, TP cannot obtain Alice and Bob’s secrets and only knows their comparison result. However, in this paper, we demonstrate that if TP is a genuine semi-honest third party, he can totally obtain Alice and Bob’s secrets by launching a particular intercept-resend-measure attack. After suggesting the intercept-resend-measure attack strategy from TP first, we put forward one corresponding improvement to prevent this attack.

Efficient scheme for remote preparation of an arbitrary tripartite four-particle entangled state

We propose a novel scheme to realize remote preparation of an arbitrary tripartite four-particle entangled state via two three-particle GHZ states as the quantum channel. In this scheme, the sender should employ several novel two-particle projective measurements on her particles. According to the sender’s measurement outcome, the receiver will carry out local unitary operations and suitable C-NOT gates on his particles to recover the desired state. It is shown that, in our scheme, the total successful probability of the RSP can reach 1.

Two-party quantum key agreement protocol with four-particle entangled states

Based on four-particle entangled states and the delayed measurement technique, a two-party quantum key agreement protocol is proposed in this paper. In the protocol, two participants can deduce the measurement results of each other’s initial quantum states in terms of the measurement correlation property of four-particle entangled states. According to the corresponding initial quantum states deduced by themselves, two parties can extract the secret keys of each other by using the publicly announced value or by performing the delayed measurement, respectively. This guarantees the fair establishment of a shared key. Since each particle in quantum channel is transmitted only once, the protocol is congenitally free from the Trojan horse attacks. The security analysis shows that the protocol not only can resist against both participant and outsider attacks but also has no information leakage problem. Moreover, it has high qubit efficiency.

The -type four-particle entangled state generated by using superconducting artificial atoms with broken symmetry

We propose a scheme for generating a genuine -type four-particle entangled state of superconducting artificial atoms with broken symmetry by using one-dimensional transmission line resonator as a data bus. With the help of the Circuit quantum electrodynamics system composed of -type three-level artificial atoms and transmission line resonator, our scheme also has long coherence time and storage time. Meanwhile, the -type three-level artificial atom used in the scheme is different from natural atom and has cyclic transitions. Furthermore, our scheme is easy to control and flexible. Through a suitable choice of the Rabi frequencies and detunings of the classical fields, we can use this system to implement the selective coupling between two arbitrary qubits. After suitable interaction time and simple operations, the desired entangled state can be obtained. Since artificial atomic excited states and photonic states are adiabatically eliminated, our scheme is robust against the spontaneous emissions of artificial atoms and the decays of transmission line resonator. We also analyze the performance and the experimental feasibility of the scheme, and show that our scheme is feasible under existing experimental conditions.

Two Schemes for Probabilistic Remote Preparation of a Four-Particle Entangled Cluster-Type State

Using partial entangled states as the quantum channel, two schemes for probabilistic remote preparation of the four-particle cluster-type state with real and complex coefficients are presented. In the first scheme, the sender and the receiver share two partial Bell states and one partial three-qubit GHZ stats as the quantum channel, and the sender can help a remote receiver to prepare a four-particle entangled cluster-type state by using three-qubit projective measurements with certain probability. In the second scheme, the quantum channel is composed of two partial three-qubit GHZ states, the remote state preparation (RSP) can be successfully realized via the positive operator valued measure (POVM), and the two-particle projective measurements are also needed in this process. The total success probability and classical communication cost are calculated.

Deterministic assisted clone of an unknown four-particle entangled cluster-type state

Two deterministic schemes are proposed to realize the assisted clone of an unknown four-particle entangled cluster-type state. The schemes include two stages. The first stage requires teleportation via maximal entanglement as the quantum channel. In the second stages of the protocols, two novel sets of mutually orthogonal basis vectors are constructed. With the assistance of the preparer through a four-particle or two-step two-particle projective measurement under these bases, the perfect copy of an original state can be produced. Comparing with the previous protocols which produce the unknown state and its orthogonal complement state at the site of the sender, the proposed schemes generate the unknown state deterministically.

Controlled Dense Coding with Four-Particle Entangled State

Two schemes, via generalized measurement and entanglement concentration respectively, for dense coding are investigated by using a four-particle entangled state, in which the supervisor can control the average amount of information transmitted from the sender to the receiver by adjusting the local measurement angle. It is shown that the results for the average amounts of information are unique from the different two schemes.

Deterministic joint remote preparation of arbitrary four-particle genuine entangled state

A novel deterministic joint remote preparation scheme of arbitrary four-particle genuine entangled state from one sender to either of two receivers is proposed. Two three-particle Green-Horne-Zeilinger (GHZ) states and one four-particle GHZ state are used as the quantum channel. The presented scheme is realized through orthogonal projective measurement of the Hadamard transferred basis and recovery operation U |ijk〉 . Some useful and general measurement bases have been constructed. The classical communication cost of the presented scheme is also calculated. Our analysis confirms the feasibility and validity of the proposed method, and shows that it has a 100% probability of success in preparation of the target quantum state.

On the "Deterministic Secure Quantum Communication using Four-Particle Entangled State and Entanglement Swapping"

Recently, Xiu et al. proposed a deterministic secure quantum communication (DSQC) protocol using the entanglement swapping of four-particle genuine entangled states. Later, Qin et al. showed a double-CNOT attack on the protocol and also provided an improvement to avoid the attack. This work tries to use a batch of decoy single photons prepared randomly in one of four different states, to enhance the qubit efficiency on their DSQC protocols and avoid the double-CNOT attack at the same time.

A Ping-Pong Quantum Dialogue Scheme Using Genuine Four-Particle Entangled States

Based on the genuine four-particle entangled state (Yeo and Chua in Phys. Rev. Lett. 96:060502, 2006) and the ping-pong protocol (Bostrom and Felbinger in Phys. Rev. Lett. 89:187902, 2002), an efficient quantum dialogue scheme is proposed. Since some subtle methods are employed, the information leakage doesn’t exist in this scheme. There are two security-check processes in this scheme, one is accomplished by using the four-particle entanglement pairs and the other by using the d particles.

Generation of a genuine four-particle entangled state of trap ions

We present a scheme for the generation of a genuine four-qubit entangled state in an ion trap. This state has many interesting entanglement properties and possible applications in quantum information processing and fundamental tests of quantum physics. In our scheme, the ion is driven by a standing-wave field, whose frequency is resonant with the ion carrier transition. By adjusting the phase of the field, both the vibration mode population and the ionic carrier excitation can be avoided. So our scheme is insensitive to the vibration states, which is important in view of decoherence.

Remote preparation of a four-particle entangled cluster-type state

Our concern is to remotely prepare a four-particle entangled cluster-type state with high success probabilities. By constructing some useful measurement bases, two novel schemes via different entanglement resources as the quantum channel are designed: one is via an EPR pair and two three-particle GHZ states; the other is via two four-qubit GHZ states. It is shown that through four-particle projective measurements under the novel sets of mutually orthogonal basis vectors, the original state can be successfully prepared with the probabilities 1 2 and 1, respectively. These schemes are extended to the non-maximally entangled quantum channel. Compared with the previous remote preparation proposal, the success probabilities of the proposed schemes are greatly improved. Furthermore, the classical communication costs of these schemes are calculated to determine the classical resources required.

Secure four-site distribution and quantum communication of χ−type entangled states

The research of multi-particle entanglement is a hot topic because of its important applications and far-reaching effects on vast aspects of quantum information. The article is devoted to the χ− type entangled state, a peculiar four-particle entangled state, which is different from a four-particle GHZ or W state under stochastic local operations and classical communication (SLOCC). Secure four-site distribution using decoy particles is proposed. Moreover, applying it, several communication protocols are presented, including four-party hierarchical quantum secret sharing, supervisory three-party asymmetric deterministic secure quantum communication, etc. The security of the four-site distribution and the communication protocols are also analyzed.

A Protocol for Bidirectional Quantum Secure Communication Based on Genuine Four-Particle Entangled States

By swapping the entanglement of genuine four-particle entangled states, we propose a bidirectional quantum secure communication protocol. The biggest merit of this protocol is that the information leakage does not exist. In addition, the ideas of the “two-step" transmission and the block transmission are employed in this protocol. In order to analyze the security of the second sequence transmission, decoy states are used.

Generation of a four-particle entangled state via cross-Kerr nonlinearity

We propose a scheme for generating a genuine four-particle polarisation entangled state |χ00) that has many interesting entanglement properties and potential applications in quantum information processing. In our scheme, we use the weak cross-Kerr nonlinear interaction between field-modes and the non-demolition measurement method based on highly efficient homodyne detection, which is feasible under the current experiment conditions.

Controlled Dense Coding with a Four-Particle Non-maximally Entangled State

Two schemes for controlled dense coding with a four-particle entangled state are investigated, one with entanglement concentration and the other with generalized measurement. In these protocols, the supervisor (Cliff) can control the average amount of information transmitted from the sender (Alice and David) to the receiver (Bob) only by adjusting his local measurement angle θ. It is shown that the results for the average amounts of information are unique from the different two schemes.

Scheme for remotely preparing a four-particle entangled cluster-type state

A protocol for remotely preparing a four-particle entangled cluster-type state by a set of new four-particle orthogonal basis projective measurement. It is secure that the entangled four-particle cluster-type state can be successfully realized at Bob place. Moreover we have also investigated that quantum channel shared by Alice and Bob is composed of four non-maximally entangled states. It is shown that Bob can also reestablish the original state (to be prepared remotely) with certain probability by means of appropriate unitary transformation.