Quantum-dot single-photon sources for the quantum internet

High-performance quantum light sources based on semiconductor quantum dots coupled to microcavities are showing their promise in long-distance solid-state quantum networks.Comment: Invited commentary for Nature Nanotechnology 202

Demonstration of Shor's quantum factoring algorithm using photonic qubits

We report an experimental demonstration of a complied version of Shor's algorithm using four photonic qubits. We choose the simplest instance of this algorithm, that is, factorization of N=15 in the case that the period $r=2$ and exploit a simplified linear optical network to coherently implement the quantum circuits of the modular exponential execution and semi-classical quantum Fourier transformation. During this computation, genuine multiparticle entanglement is observed which well supports its quantum nature. This experiment represents a step toward full realization of Shor's algorithm and scalable linear optics quantum computation.Comment: small changes over v2; to appear in PR

Study on the Performance of New Imidazoline Electromigration Inhibitor in Reinforced Concrete

Steel bars inside reinforced concrete easily become corroded in high chloride environments, bidirectional electromigration rehabilitation is an important method of repairing the durability of reinforced concrete, it can migrate chloride out of concrete and transfer electromigration inhibitor to the surface of the steel bar under the action of an electric field. In this paper, autonomous synthesis electromigration inhibitor was used with bidirectional electromigration rehabilitation to repair the durability of reinforced concrete. Specifically, the effect of a new imidazoline corrosion inhibitor on chloride migration, corrosion potential, and reinforcement of concrete strength was explored. The research results showed that the dechlorination effect and electrochemical dechlorination made no significant difference on the surface of the concrete, where chlorine removal efficiency was more than 70% and the location of steel efficiency of chlorine was more than 90%. The autonomous synthesis electromigration inhibitor was found to be excellent at facilitating chloride migration and ameliorating corrosion, meanwhile, it had a negligible impact on the concrete strength

Multi-photon entanglement and interferometry

Multi-photon interference reveals strictly non-classical phenomena. Its applications range from fundamental tests of quantum mechanics to photonic quantum information processing, where a significant fraction of key experiments achieved so far comes from multi-photon state manipulation. We review the progress, both theoretical and experimental, of this rapidly advancing research. The emphasis is given to the creation of photonic entanglement of various forms, tests of the completeness of quantum mechanics (in particular, violations of local realism), quantum information protocols for quantum communication (e.g., quantum teleportation, entanglement purification and quantum repeater), and quantum computation with linear optics. We shall limit the scope of our review to "few photon" phenomena involving measurements of discrete observables.Comment: 71 pages, 38 figures; updated version accepted by Rev. Mod. Phy

Toolbox for entanglement detection and fidelity estimation

The determination of the state fidelity and the detection of entanglement are fundamental problems in quantum information experiments. We investigate how these goals can be achieved with a minimal effort. We show that the fidelity of GHZ and W states can be determined with an effort increasing only linearly with the number of qubits. We also present simple and robust methods for other states, such as cluster states and states in decoherence-free subspaces.Comment: 5 pages, no figures, v3: final version, to appear as a Rapid Communication in PR

Experimental Study on the Impact Fatigue Behavior of GFRP Mesh Reinforced ECC for Runway Pavement Application

Concrete pavement is easy to crack and generate the chunks, which may destroy the engine of the airplane and maintenance cost is very expensive. Engineered cementitious composites (ECC) is ductile with microcracks, but its strength is low. Glass Fiber Reinforced Polymer (GFRP) mesh imbedded in ECC could improve the strength. This paper investigates the impact fatigue behaviour of ECC and GFRP mesh reinforced ECC under 5 different impact pressures (1.61 MPa, 1.88 MPa, 2.10 MPa, 2.41 MPa and 3.60 MPa), the concrete specimens were also tested for comparison. The pulse velocity through the specimens was also tested to analyse the damage of the specimens. The experimental results show that GFRP mesh reinforced ECC has improved impact fatigue behaviour than ECC specimens. The concrete specimens were all broken after a few impacts, but the GFRP mesh reinforced ECC specimens were all not broken after impacted for 30000 times. The impact fatigue behaviour of ECC reinforced with two layers of GFRP mesh with a grid dimension of 10 mm was the best, which is a desirable pavement composite comparing to the ordinary concrete and ECC without reinforcements