Gate defined quantum dot realized in a single crystalline InSb nanosheet

Single crystalline InSb nanosheet is an emerging planar semiconductor material with potential applications in electronics, infrared optoelectronics, spintronics and topological quantum computing. Here we report on realization of a quantum dot device from a single crystalline InSb nanosheet grown by molecular-beam epitaxy. The device is fabricated from the nanosheet on a Si/SiO2 substrate and the quantum dot confinement is achieved by top gate technique. Transport measurements show a series of Coulomb diamonds, demonstrating that the quantum dot is well defined and highly tunable. Tunable, gate-defined, planar InSb quantum dots offer a renewed platform for developing semiconductor-based quantum computation technology.Comment: 12 pages, 4 figure

Anisotropic Pauli spin-blockade effect and spin-orbit interaction field in an InAs nanowire double quantum dot

We report on experimental detection of the spin-orbit interaction field in an InAs nanowire double quantum dot device. In the spin blockade regime, leakage current through the double quantum dot is measured and is used to extract the effects of spin-orbit interaction and hyperfine interaction on spin state mixing. At finite magnetic fields, the leakage current arising from the hyperfine interaction is suppressed and the spin-orbit interaction dominates spin state mixing. We observe dependence of the leakage current on the applied magnetic field direction and determine the direction of the spin-orbit interaction field. We show that the spin-orbit field lies in a direction perpendicular to the nanowire axis but with a pronounced off-substrate-plane angle. It is for the first time that such an off-substrate-plane spin-orbit field in an InAs nanowire has been detected. The results are expected to have an important implication in employing InAs nanowires to construct spin-orbit qubits and topological quantum devices.Comment: 20 pages, 5 figures, Supporting Informatio

Adjustable capability of the distributed energy system:Definition, framework, and evaluation model

The adjustable capability of distributed energy systems responding to the incentives of the upper energy supply system has been significantly improved by energy storage and renewable energy technologies. Most existing research focuses on evaluating the flexibility of distributed energy system itself or the demand response potential of end-users, but there is no specific model which takes the distributed energy system as an integrated load and evaluates its adjustable capability from the perspective of the upper energy supply system. To fill the research gap, this paper defines the adjustable capability of distributed energy systems, describes its characteristics, and proposes a unified evaluation model. Then, from the perspective of energy demand and supply sides, it quantifies the impact of each influential factor in different energy links on the adjustable capability and studies the interactive mechanism between devices within the system. Thereafter, the adjustable capability of distributed energy systems under typical scenarios at a single moment is evaluated, and the impact of economic constraints on the adjustable capability is also extensively analyzed. Accordingly, this paper proposes a sequential recurrence method to evaluate the adjustable capability of distributed energy systems against three different initial states: unknown initial state, fixed initial state, uncertain initial state. Finally, the adjustable capability concept is demonstrated on a practical industrial park to verify the effectiveness and practicability. This study deepens the connection between distributed energy systems and upper energy supply system in the Energy Internet at the energy information level. Which enables distributed energy system to quantize its energy demand range for the upper energy supply system and realize its own reliable operation and rolling optimization. In addition, this evaluation method allows upper energy supply system to plan, overhaul and dispatch more economically and reliably on the basis of understanding the energy demand of distributed energy system. Moreover, upper energy supply system can formulate the demand response strategy with the maximum revenue by balancing the size of adjustable capability interval of distributed energy system and the investment cost of demand response.</p

Adjustable capability of the distributed energy system:Definition, framework, and evaluation model

The adjustable capability of distributed energy systems responding to the incentives of the upper energy supply system has been significantly improved by energy storage and renewable energy technologies. Most existing research focuses on evaluating the flexibility of distributed energy system itself or the demand response potential of end-users, but there is no specific model which takes the distributed energy system as an integrated load and evaluates its adjustable capability from the perspective of the upper energy supply system. To fill the research gap, this paper defines the adjustable capability of distributed energy systems, describes its characteristics, and proposes a unified evaluation model. Then, from the perspective of energy demand and supply sides, it quantifies the impact of each influential factor in different energy links on the adjustable capability and studies the interactive mechanism between devices within the system. Thereafter, the adjustable capability of distributed energy systems under typical scenarios at a single moment is evaluated, and the impact of economic constraints on the adjustable capability is also extensively analyzed. Accordingly, this paper proposes a sequential recurrence method to evaluate the adjustable capability of distributed energy systems against three different initial states: unknown initial state, fixed initial state, uncertain initial state. Finally, the adjustable capability concept is demonstrated on a practical industrial park to verify the effectiveness and practicability. This study deepens the connection between distributed energy systems and upper energy supply system in the Energy Internet at the energy information level. Which enables distributed energy system to quantize its energy demand range for the upper energy supply system and realize its own reliable operation and rolling optimization. In addition, this evaluation method allows upper energy supply system to plan, overhaul and dispatch more economically and reliably on the basis of understanding the energy demand of distributed energy system. Moreover, upper energy supply system can formulate the demand response strategy with the maximum revenue by balancing the size of adjustable capability interval of distributed energy system and the investment cost of demand response.</p

A real-time ultrasonic technique for viscosity monitoring during polymer processing

Peer reviewed: YesNRC publication: Ye

Ultrasonic characterization of the crystallization behavior of poly(ethylene terephthalate)

Based on previous observations that the ultrasonic signals are sensitive to the crystallization of polymers (Tatibouet, J., Pich\ue9, L. Polymer 1991, 32, 3147), we have expanded our efforts to study the detail relationship between the ultrasonic signals and crystallization process in the present work. The nonisothermal and isothermal crystallization of virgin poly(ethylene terephthalate) (PET) and PET samples after degradation were studied by using a specially designed pressure-volume-temperature (PVT) device, with which an ultrasonic detector was combined. The results showed that the evolution of the ultrasonic signals not only can be used to probe the crystallization process, but also can qualitatively characterize crystallization rate, crystallinity, crystallite size and amorphous. DSC measurement was used to verify such results. Ultrasonic signals could be as a complementary tool to polymer chain movement and well be applied to characterize the crystallization behaviour. Furthermore, the ultrasonic measurement has the potential use to characterize crystallization of products in-line during processing (i.e., injection molding, microcoulding).Sur la base d\u2019observations pr\ue9c\ue9dentes indiquant que les signaux ultrasoniques sont sensibles \ue0 la cristallisation des polym\ue8res (Tatibouet et Pich\ue9, Polymer 1991, 32, 3147), on a poursuivi nos efforts afin d\u2019\ue9tudier en d\ue9tail la relation entre les signaux ultrasoniques et le processus de cristallisation. On a \ue9tudi\ue9 la cristallisation isotherme et la cristallisation non isotherme d\u2019\ue9chantillons de poly(t\ue9r\ue9phtalate d\u2019\ue9thyl\ue8ne) (PTE) vierge et d\u2019\ue9chantillons de PTE apr\ue8s d\ue9gradation au moyen d\u2019un dispositif pression volume-temp\ue9rature sp\ue9cialement con\ue7u et d\u2019un d\ue9tecteur \ue0 ultrasons. Les r\ue9sultats montrent que l\u2019\ue9volution des signaux ultrasoniques peut non seulement servir \ue0 suivre le processus de cristallisation, mais aussi permettre de caract\ue9riser qualitativement la vitesse de cristallisation, la cristallinit\ue9, la taille des cristallites et le caract\ue8re amorphe. On a utilis\ue9 des mesures de CCP pour v\ue9rifier ces r\ue9sultats. Les signaux ultrasoniques pourraient servir d\u2019outil compl\ue9mentaire pour le mouvement de la cha\ueene polym\ue8re et pourraient \ueatre utilis\ue9s pour caract\ue9riser le comportement \ue0 la cristallisation. De plus, la mesure ultrasonique peut \ueatre utilis\ue9e pour caract\ue9riser la cristallisation de produits en ligne pendant leur traitement (p. ex., moulage par injection et micromoulage).Peer reviewed: YesNRC publication: Ye

Impact of DG Configuration on Maximum Use of Load Supply Capability in Distribution Power Systems

Traditional distributed generators (DGs) planning methods take network loss minimization as the main objective to optimize DG sites in feeders. The use of load supply capability (LSC) in DG planning will precisely answer the questions how many DGs should be integrated, which transformer they should be connected to, and which type of DGs should be adopted. The main work of this paper is to analyze the impact of DGs on LSC so as to answer the three key questions. It resolves the planning problem through three steps: (i) two LSC models considering DGs’ access are developed, in which two different transfer strategies are considered: direct load transfer and indirect load transfer; (ii) the method of combined simple method and point estimate method is proposed. At last, based on a base case, when the configuration of DGs is changing, the impact of DGs on system LSC is studied. After the case study, the conclusion concerning the impact of load transfer strategy, DG capacities, and DG types on LSC is reached