Producing cluster states in charge qubits and flux qubits

We propose a method to efficiently generate cluster states in charge qubits, both semiconducting and superconducting, as well as flux qubits. We show that highly-entangled cluster states can be realized by a `one-touch' entanglement operation by tuning gate bias voltages for charge qubits. We also investigate the robustness of these cluster states for non-uniform qubits, which are unavoidable in solid-state systems. We find that quantum computation based on cluster states is a promising approach for solid-state qubits.Comment: 4 pages, 1 figure

Efficient purification protocols using iSWAP gates in solid-state qubits

We show an efficient purification protocol in solid-state qubits by replacing the usual bilateral CNOT gate by the bilateral iSWAP gate. We also show that this replacement can be applied to breeding and hashing protocols, which are useful for quantum state purification. These replacements reduce the number of fragile and cumbersome two-qubit operations, making more feasible quantum-information-processing with solid-state qubits. As examples, we also present quantitative analyses for the required time to perform state purification using either superconducting or semiconducting qubits.Comment: 10 pages, 5 figure

Polypropylene Blend with Polyphenols through Dynamic Vulcanization: Mechanical, Rheological, Crystalline, Thermal, and UV Protective Property

International audienceTannin and lignin were blended with polypropylene (PP) through dynamic vulcanization technique. Their influence of mechanical property, crystallinity, thermal stability, as well as ultraviolet (UV) protection property on the PP matrix was investigated and compared with native tannin and lignin. According to our experimental results, tannin and lignin undergo dynamic vulcanization and were more compatible with the PP matrix. Besides, tannin and vulcanized tannin can perform as nucleating agents of PP because of their relatively small particle size. Moreover, vulcanized tannin/lignin have a better performance on the thermal stability of PP compared with native tannin/lignin, especially PP/vulcanized lignin blend. Furthermore, vulcanized tannin/lignin present better UV protective performance, concluded from fewer changes on surface morphology, carbonyl index, crystallinity, viscosity, and tensile property

Size-dependent decoherence of excitonic states in semiconductor microcrystallites

The size-dependent decoherence of the exciton states resulting from the spontaneous emission is investigated in a semiconductor spherical microcrystallite under condition $a_{B}\ll R_{0}\leq\lambda$. In general, the larger size of the microcrystallite corresponds to the shorter coherence time. If the initial state is a superposition of two different excitonic coherent states, the coherence time depends on both the overlap of two excitonic coherent states and the size of the microcrystallite. When the system with fixed size is initially in the even or odd coherent states, the larger average number of the excitons corresponds to the faster decoherence. When the average number of the excitons is given, the bigger size of the microcrystallite corresponds to the faster decoherence. The decoherence of the exciton states for the materials GaAs and CdS is numerically studied by our theoretical analysis.Comment: 4 pages, two figure

Strong coupling of a spin qubit to a superconducting stripline cavity

We study electron-spin-photon coupling in a single-spin double quantum dot embedded in a superconducting stripline cavity. With an external magnetic field, we show that either a spin-orbit interaction (for InAs) or an inhomogeneous magnetic field (for Si and GaAs) could produce a strong spin-photon coupling, with a coupling strength of the order of 1 MHz. With an isotopically purified Si double dot, which has a very long spin coherence time for the electron, it is possible to reach the strong-coupling limit between the spin and the cavity photon, as in cavity quantum electrodynamics. The coupling strength and relaxation rates are calculated based on parameters of existing devices, making this proposal experimentally feasible.Comment: 6 pages, 2 figures. Published versio

Dynamics of entanglement for coherent excitonic states in a system of two coupled quantum dots and cavity QED

The dynamics of the entanglement for coherent excitonic states in the system of two coupled large semiconductor quantum dots ($R/a_{B}\gg 1$) mediated by a single-mode cavity field is investigated. Maximally entangled coherent excitonic states can be generated by cavity field initially prepared in odd coherent state. The entanglement of the excitonic coherent states between two dots reaches maximum when no photon is detected in the cavity. The effects of the zero-temperature environment on the entanglement of excitonic coherent state are also studied using the concurrence for two subsystems of the excitonsComment: 7 pages, 6 figure

Isocyanate-Free Polyurethane Coatings and Adhesives from Mono- and Di-Saccharides

Mostly biosourced non-isocyanate polyurethanes (NIPU) were prepared from mono- and disaccharides, namely glucose and sucrose, reacted with dimethyl carbonate and hexamethylene diamine. The main aim of this research was to show that NIPU can be prepared from mono- and disaccharides, this just being an initial exploratory work and its sole main aim. The oligomers obtained were detected by MALDI-ToF, CP-MAS 13C NMR, and FTIR spectrometries. The glucose-derived NIPU were shown to harden at a markedly lower temperature than the sucrose-derived ones and to be easier to handle and spread. The NIPU obtained were applied as wood and steel surface coatings and tested by the sessile drop test (on wood) and cross-cut test (on steel) with encouraging results. The glucose NIPU gave good surface coating results already at 103 °C, while the sucrose NIPU yielded good results only at a markedly higher temperature of hardening. The NIPU saccharide resins were also tested as thermosetting wood joint adhesives with the glucose NIPU yielding very encouraging results

Développement d'adhésifs industriels à base de biomatériaux et de mélamine sans formaldéhyde

In this research, there are two main parts works, first is based on melamine glyoxal resin without formaldehyde used, and the modification of it use for wood industry adhesives. The other part is the preparation of environmentally friendly adhesives and non-isocyanate polyurethane(NIPU) from biomass-based (sugar, protein, tannin, etc.). Wood composites such as plywood and particleboard were used for easuring the performance of adhesives, and more possibilities applications of them such as coating and foams were tried also. 13C-NMR, Fourier Transform Infra-Red (FTIR), Matrix assisted laser desorption ionization time-of-flight (MALDI-TOF), thermomechanical analysis(TMA), Differential scanning calorimetry(DSC) and other instruments help to analyze structures and thermodynamic properties of adhesives. The descriptions of specific works are as follows: 1) Synthetic melamine-glyoxal resin without use toxic formaldehyde and a suitable hardener was found for it. By the modification of glutaraldehyde, a melamine-glyoxal-glutaraldehyde(MGG') resin with good performance was prepared and used for plywood production, which can replace the industrial Urea-formaldehyde resin wood adhesive. In addition, 5-hydroxymethylfurfural as a chemical reagent derived from biomass material was also used to modify MG resin to improve its bonding performance and water resistance. 2) The biomass material furfuryl alcohol was used to react with aldehydes (formaldehyde, glyoxal, glutaraldehyde) to prepare plywood adhesives. Among them, furfuryl alcohol-glyoxal(FAG) resin, which was reacted with a non-toxic glyoxal, and with a good bonding propertiesis. It’s as an environmentally friendly adhesive for wood bongding. The effect of different acidity of curing agents on bonding performance has also been explored, a self-neutralizing hardener is synthesized and used. 3) Proteins, tannins were used to prepare bio-based environmentally friendly wood adhesives, and improved the bonding properties and water resistance by the addition of crosslinking agents (furfuryl alcohol-glyoxal resins, epoxy resins, polyethyleneimine, etc.). 4) Biomass materials such as monosaccharide and disaccharide were used to synthesize non-isocyanate polyurethane(NIPU), and used for plywood or particleboard to obtain bio-based NIPU adhesives with excellent performance. The effect of several crosslinkers on the curing temperature and bonding properties of NIPU was also studied. Research on more application about NIPU have also been conducted, for example, coating and rigid foams.Dans cette recherche, il y a deux parties principales : la première est basée sur la résine mélamine-glyoxal sans utilisation de formaldéhyde, et sa modification pour qu’elle soit utilisée comme adhésifs pour bois. La deuxième partie concerne la préparation d'adhésifs écologiques et de polyuréthane non isocyanate (NIPU) à partir de biomasse (sucre, protéines, tanins, etc.). Des composites de bois tels que le contreplaqué et les panneaux de particules sont confectionnés pour mesurer la performance des adhésifs, et de nombreuses autres applications telles que le revêtement de surface et les mousses sont également testées. RMN-13C, Spectroscopie infrarouge à transformée de Fourier (FTIR), La spectrométrie de masse MALDI-TOF, analyse thermomécanique (TMA), La calorimétrie différentielle à balayage (DSC) et d’autres instruments permettant d'analyser les structures et les propriétés thermodynamiques des adhésifs. Les descriptions d'œuvres spécifiques sont les suivantes : 1)Une résine sans formaldéhyde à base de mélamine-glyoxal toxique a été synthétisé et un nouveau durcisseur à base d’acide ionique a été préparé. Le glutaraldéhyde a été utilisé pour synthétiser la résine mélamine-glyoxal-glutaraldéhyde (MGG ') et qui a donné des contreplaqués bonnes performances, permettant ainsi de remplacer sans doute la résine urée-formaldéhyde. En outre, le 5-hydroxyméthylfurfural, réactif chimique dérivé de la biomasse a été également utilisé pour modifier la résine MG afin d’améliorer ses performances de liaison et sa résistance à l’eau. 2)L’alcool furfurylique, issus de la biomasse, a été utilisé pour réagir avec des aldéhydes (formaldéhyde, glyoxal, glutaraldéhyde) afin de préparer des adhésifs pour le contreplaqué. La résine d’alcool furfurylique-glyoxal (FAG), où d’alcool furfurylique est réagi avec le glyoxal qui n’est pas toxique. La résine a donné de bonnes propriétés mécaniques et d’adhésion. C’est un adhésif écologique pour le collage du bois. L'effet de l’acidité des durcissements sur les performances de collage a été également étudié. Un durcisseur auto-neutralisant est synthétisé et utilisé. 3)Les protéines, les tanins sont aussi utilisés pour préparer des adhésifs à base de bois respectueux à l’environnementont, tout en améliorant les propriétés de liaison et la résistance à l'eau grâce à l'ajout des agents de réticulation tels que la résines alcool furfurylique-glyoxal, résines époxy, polyéthylèneimine, ..etc. 4)Des matériaux à base de biomasse tels que le monosaccharide, le disaccharide et la protéine de soja ont été utilisés pour synthétiser du polyuréthane non isocyanate (NIPU) biosourcés, utilisés pour le contreplaqué et les panneaux de particules ont permis d’obtenir des panneaux d’excellents performances. L'effet de plusieurs agents de réticulation sur la température de durcissement et les propriétés de liaison de NIPU a également été étudié. Les résines NIPU ont été appliqués dans les revêtements et les mousses rigides