Quantum Teleportation via Hybrid Entangled States

In this paper, we study quantum teleportation of atomic states via a hybrid entangled state (HES) involving an atom and a cavity field. And we investigate how to implement controlled phase (CP) gates between atomic internal states and coherent states of cavity field. We also discuss the methods of distinguishing coherent states |±α〉in a cavity. Finally, a brief discussion about the feasibility of this scheme in experiment is presented.     

Quantum Classifier with Entangled Subgraph States

International Journal of Theoretical Physics - With the development of quantum computation theory, some researchers further apply it to improve the efficiency of classical machine learning...     

Quantum Teleportation via Hybrid Entangled States

In this paper, we study quantum teleportation of atomic states via a hybrid entangled state (HES) involving an atom and a cavity field. And we investigate how to implement controlled phase (CP) gates between atomic internal Finally, a brief discussion about the feasibility of this scheme in experiment is presented.     

Quantum Dynamics of Bound Entangled States

By using the partial transpose and realignment method, we study the time evolution of the bound entanglement under the bilinear-biquadratie Hamiltonian. For the initial Horodecki＇s bound entangled state, it keeps bound entangled for some time, while for the initial bound entangled states constructed from the unextendable product basis, they become free once the time evolution begins. The time evolution provides a new way to construct bound entangled states, and also gives a method to free bound entanglement.     

连续变量量子纠缠态的非对称量子克隆

该文讨论了连续变量量子纠缠态非对称克隆过程,从理论上讨论了在Local e-cloner方案中,入射和出射分束器的反射率可变情况下的纠缠态克隆,并利用纠缠不可分判据分析了所获得的非对称克隆纠缠态的纠缠特性.结果指出,克隆得到的两组纠缠态的纠缠特性不相同.     

Controlled Quantum Dialogue with Five-Qubit Entangled States

In this paper, a controlled quantum dialogue protocol is designed based on five-qubit entangled states. One five-qubit entangled state can be used to exchange one communicant’s two private bits with the other communicant’s two private bits under the control of an honest supervisor. Security analysis turns out that it can overcome the information leakage problem and can resist the active attacks from an outside attacker. The designed protocol only needs single-particle measurements and Bell state measurements, both of which can be realized with current technologies.

     

Quantum Byzantine Agreement with Tripartite Entangled States

We present a quantum protocol for resolving the detectable Byzantine agreement (BA) problem using tripartite Greenberger–Horne–Zeilinger(GHZ)-like states and homodyne measurements in the continuous variable (CV) scenario. The protocol considers the simplest (i.e., three-player) BA problem involving one broadcaster and two receivers who jointly participant in the distribution, test, and agreement phases. The GHZ-like states provide the quantum resources for implementing the primitive of BA and satisfy a priori entanglement bound. Analyses demonstrate that the proposed quantum solution adheres to the agreement, validity, and termination criteria. Conveniently, the beam splitter strategy along with photon detection offers a method for comparing quantum messages. The paper shows that a potential high-efficiency CV-based BA protocol can be achieved using standard off-the-shelf components in quantum optics, maintaining the desirable characteristics of CVs when compared with discrete-variable BA protocol.

     

Quantum Secret Sharing with Two-Particle Entangled States

We present a new protocol for the quantum secret sharing （QSS） task among multiparties with two-particle entangled states. In our scheme, the secret is split among a number of participatlng partners and the reconstruction requires collaboration of all the authorized partners. Instead of multiparticle Greenberger-Horne-Zeillnger states, only two-particle entangled states are employed in this scheme. By local operations and individual measurements on either of the two entangled particles, each authorized partner obtains a sequence of secret bits shared with other authorized partners. This protocol can be experimentally realized using only linear optical elements and simple entanglement source. It is scalable in practice.     

Continuous-Variable Quantum Teleportation of Entangled Coherent States

We propose a quantum teleportation scheme for tripartite entangled coherent state （ECS） with continuous variable. Our scheme is feasible and economical in the sense that we need only linear optical devices such as beam splitters, phase shifters and photon detectors and employ three bipartite maximally ECSs as quantum channels. We also generalize the tripartite scheme into multipartite ease and calculate the minimum average fidelity for the schemes in tripartite and multipartite cases.     

Quantum Private Comparison Based on GHZ Entangled States

We present a new quantum private comparison protocol based on the three-particle GHZ states. In this protocol, we prepare two types of GHZ states and use their entanglement properties to encode and compare the private information of X and Y. We also discuss that our protocol can withstand all various kinds of outside attacks and participant attacks.     

Two-Party Quantum Private Comparison with Five-Qubit Entangled States

In this paper, a two-party quantum private comparison (QPC) protocol is proposed by using five-qubit entangled states as the quantum resource. The proposed protocol needs the help from a semi-honest third party (TP), who is allowed to misbehave on his own but not allowed to conspire with the adversary including the dishonest user. The proposed protocol has the following distinct features: (1) One five-qubit entangled state can be used to achieve the equality comparison of two bits in each round of comparison; (2) Neither unitary operations nor quantum entanglement swapping technology is needed, both of which may consume expensive quantum devices; (3) Only Bell measurements and single-particle measurements are employed, both of which can be realized with current quantum technologies; (4) The security toward both the outside attack and the participant attack can be guaranteed; (5) The private information of two parties is not leaked out to TP.     

Quantum Key Agreement Via Non-maximally Entangled Cluster States

International Journal of Theoretical Physics - In this paper, we present a quantum key agreement (QKA) protocol with non-maximally entangled four-qubit cluster states. In our scheme, each...     

Quantum Private Comparison Using Genuine Four-Particle Entangled States

In this paper, a quantum private comparison protocol is proposed based on χ-type state. According to the protocol, two parties can determine the equality of their information with the assistant of a semi-honest third party. Due to utilizing quantum superdense coding, this protocol provides a high efficiency and capacity. Moreover, its security is also discussed.     

Two-Party Quantum Private Comparison with Four-Particle Entangled States

International Journal of Theoretical Physics - A two-party quantum private comparison (QPC) protocol is constructed with four-particle entangled states, where the third party (TP) is assumed to be...     

Teleportation of Quantum States through Mixed Entangled Pairs

We describe a protocol for quantum state teleportation via mixed entangled pairs. With the help of an ancilla, near-perfect teleportation might be achieved. For pure entangled pairs, perfect teleportation might be achieved with a certain probability without using an ancilla. The protocol is generalized to teleportation of multiparticle states and quantum secret sharing.     

Novel Quantum Deterministic Key Distribution Protocols with Entangled States

By utilizing Bell states and GHZ states, two quantum deterministic key distribution (QDKD) protocols are presented to hand over the previously deterministic key to the intended receiver. The proposed QDKD protocols have two-way authentications, and then the eavesdropping and impersonation can be detected easily. The deterministic key itself is not transmitted over the channel and the receiver Bob infers his key in an indirect manner with the relationship between Alice’s messages and his own measurement results, which guarantees the security of the deterministic key. Different from the quantum key distribution protocols yielding random keys, the proposed QDKD protocols can distribute the pre-deterministic keys securely, which are of great significance in the filed of key management.     

Quantum Private Comparison Protocol Based on Bell Entangled States

In this paper,a quantum private comparison protocol is proposed based on bell entangled states.In our protocol,two parties can compare the equality of their information with the help of a semi-honest third party.The correctness and security of our protocol are discussed.One party cannot learn the other's private information and the third party also cannot learn any information about the private information.     

Quantum Multi-valued Byzantine Agreement Based on d-dimensional Entangled States

Byzantine agreement has always been an important research topic of distributed computing and has been widely applied to blockchain technology in recent years. We propose a quantum protocol for solving multi-valued detectable Byzantine agreement problem in this paper. Each general is firstly distributed a list that no one else knows based on d-dimensional entangled states. Then the n generals can reach an agreement in which t (where t < n/3) of them are disloyal by using these lists. Finally, it is proved that the list distribution process is secure, and the proposed protocol satisfies the definition of the multi-valued detectable Byzantine agreement.

     

Quantum Secure Direct Communication by Using General Entangled States

We revisited the quantum secure direct communication (QSDC) by using a notation (Li et al. in Phys. Lett. A 297:121, 2002; Li et al. in Int. J. Theor. Phys. 46(7):1815, 2007) and generalized QSDC to arbitrary finite dimensions, we also figured out the decoding formula for QSDC of arbitrary finite dimensions. In order to overcome the channel noisy, we present a scheme through introduce n auxilians by using quantum swapping.     

Quantum Authencryption with Two-Photon Entangled States for Off-Line Communicants

In this paper, a quantum authencryption protocol is proposed by using the two-photon entangled states as the quantum resource. Two communicants Alice and Bob share two private keys in advance, which determine the generation of two-photon entangled states. The sender Alice sends the two-photon entangled state sequence encoded with her classical bits to the receiver Bob in the manner of one-step quantum transmission. Upon receiving the encoded quantum state sequence, Bob decodes out Alice’s classical bits with the two-photon joint measurements and authenticates the integrity of Alice’s secret with the help of one-way hash function. The proposed protocol only uses the one-step quantum transmission and needs neither a public discussion nor a trusted third party. As a result, the proposed protocol can be adapted to the case where the receiver is off-line, such as the quantum E-mail systems. Moreover, the proposed protocol provides the message authentication to one bit level with the help of one-way hash function and has an information-theoretical efficiency equal to 100 %.