High-Efficiency Three-Party Quantum Key Agreement Protocol with Quantum Dense Coding and Bell States

We propose a high-efficiency three-party quantum key agreement protocol, by utilizing two-photon polarization-entangled Bell states and a few single-photon polarization states as the information carriers, and we use the quantum dense coding method to improve its efficiency. In this protocol, each participant performs one of four unitary operations to encode their sub-secret key on the passing photons which contain two parts, the first quantum qubits of Bell states and a small number of single-photon states. At the end of this protocol, based on very little information announced by other, all participants involved can deduce the same final shared key simultaneously. We analyze the security and the efficiency of this protocol, showing that it has a high efficiency and can resist both outside attacks and inside attacks. As a consequence, our protocol is a secure and efficient three-party quantum key agreement protocol.

     

High-capacity quantum secure direct communication with two-photon six-qubit hyperentangled states

This study proposes the first high-capacity quantum secure direct communication(QSDC) with two-photon six-qubit hyperentangled Bell states in two longitudinal momentum and polarization degrees of freedom(DOFs) of photon pairs, which can be generated using two 0.5 mm-thick type-I β barium borate crystal slabs aligned one behind the other and an eight-hole screen. The secret message can be independently encoded on the photon pairs with 64 unitary operations in all three DOFs. This protocol has a higher capacity than previous QSDC protocols because each photon pair can carry 6 bits of information, not just 2 or 4 bits.Our QSDC protocol decreases the influence of decoherence from environment noise by exploiting the decoy photons to check the security of the transmission of the first photon sequence. Compared with two-way QSDC protocols, our QSDC protocol is immune to an attack by an eavesdropper using Trojan horse attack strategies because it is a one-way quantum communication.The QSDC protocol has good applications in the future quantum communication because of all these features.     

Understanding the adsorption mechanism of Ni(II) on graphene oxides by batch experiments and density functional theory studies

The graphene oxides(GOs) have attracted multidisciplinary study because of their special physicochemical properties. The high surface area and large amounts of oxygen-containing functional groups make GOs suitable materials for the efficient elimination of heavy metal ions from aqueous solutions. Herein the sorption of Ni(II) on GOs was studied using batch experiments, and the results showed that the sorption of Ni(II) is strongly dependent on p H and ionic strength at pH8, and independent of ionic strength at pH8. The sorption of Ni(II) is mainly dominated by outer-sphere surface complexation and ion exchange at low p H, and by inner-sphere surface complexation at high p H. The interaction of Ni(II) with GOs was also investigated by theoretical density functional theory(DFT) calculations, and the results show that the sorption of Ni(II) on GOs is mainly attributed to the –COH and –COC groups and the DFT calculations show that Ni(II) forms stable GO_Ni_triplet structure with the binding energy of -39.44 kcal/mol, which is in good agreement with the batch sorption experimental results. The results are important for the application of GOs as adsorbents in the efficient removal of Ni(II) from wastewater in environmental pollution cleanup.     

Photo-thermal-elastic interaction in an unbounded semiconducting medium with spherical cavity due to pulse heat flux

In this work, the photothermal waves in an unbounded semiconducting medium with spherical cavity are studied. This problem is solved using the theory of coupled plasma, thermal, and elastic wave. An unbounded material, elastic semiconductor containing a spherical cavity with isotropic and homogeneous thermal and elastic properties has been considered. The inner surface of the cavity is taken traction-free and subjected to an exponentially decaying pulse boundary heat flux. Laplace transform techniques and eigenvalue approach were used to obtain the analytical solutions. Numerical computations have been done for silicon-like semiconductor material, and the results are presented graphically to estimate the effect of time and the coupling between the plasma, thermal, and elastic waves.     

Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup

Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen‐containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen‐containing functional groups using low‐temperature plasma techniques and the application of the surface‐modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO‐based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low‐temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results.     

Self-error-rejecting photonic qubit transmission in polarization-spatial modes with linear optical elements

We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom.     

Efficient Entanglement Concentration of Nonlocal Two-Photon Polarization-Time-Bin Hyperentangled States

We present two different hyperentanglement concentration protocols (hyper-ECPs) for two-photon systems in nonlocal polarization-time-bin hyperentangled states with known parameters, including Bell-like and cluster-like states, resorting to the parameter splitting method. They require only one of two parties in quantum communication to operate her photon in the process of entanglement concentration, not two, and they have the maximal success probability. They work with linear optical elements and have good feasibility in experiment, especially in the case that there are a big number of quantum data exchanged as the parties can obtain the information about the parameters of the nonlocal hyperentangled states by sampling a subset of nonlocal hyperentangled two-photon systems and measuring them. As the quantum state of photons in the time-bin degree of freedom suffers from less noise in an optical-fiber channel, these hyper-ECPs may have good applications in practical long-distance quantum communication in the future.     

Optimal Synthesis of the Joint Unitary Evolutions

Joint unitary operations play a central role in quantum communication and computation. We give a quantum circuit for implementing a type of unconstructed useful joint unitary evolutions in terms of controlled-NOT (CNOT) gates and single-qubit rotations. Our synthesis is optimal and possible in experiment. Two CNOT gates and seven R _x , R _y or R _z rotations are required for our synthesis, and the arbitrary parameter contained in the evolutions can be controlled by local Hamiltonian or external fields.     

Investigation of Q-S synchronization in coupled chaotic incommensurate fractional order systems

Chaos and synchronization in fractional order systems have received increasing attention in recent years. In this paper, the problem of Q-S synchronization for different dimensional incommensurate fractional order chaotic systems is investigated. Based on Laplace transform and stability theory of linear integer order differential systems, some synchronization schemes are designed to achieve Q-S synchronization between n-D and m-D incommensurate fractional order chaotic systems. Test problems and numerical simulations are used to show the effectiveness of the proposed approach.     

Al2O3-47 nm and Al2O3-36 nm characterizations of nonlinear differential equations for biomedical applications: Magnetized peristaltic transport

Current research models the Al₂O₃ 47nm and Al₂O₃ 36nm nanoparticles transportation through peristalsis with entropy optimization. Conservation laws for mass, momentum and energy are used to model the present flow situation. These equations elaborates the magnetohydrodynamics, Hall, thermal radiation, Joule heating, heat generation and absorption. Convective heat transfer impacts are studied at channel walls. Entropy is modeled in view of thermodynamics second law. Two different expressions for effective viscosity are accounted. Simplification of the modeled equations is done through lubrication assumptions. Solution for momentum equation is obtained analytically and for numerically for temperature equation. Built-in shooting procedure is utilized to obtain the desired numerical results. Later on these obtained results are used to sketch and discussed the flow quantities of interest for the influential parameters accounted in the problem.