The valley filter efficiency of monolayer graphene and bilayer graphene line defect model

In addition to electron charge and spin, novel materials host another degree of freedom, the valley. For a junction composed of valley filter sandwiched by two normal terminals, we focus on the valley efficiency under disorder with two valley filter models based on monolayer and bilayer graphene. Applying the transfer matrix method, valley resolved transmission coefficients are obtained. We find that: i) under weak disorder, when the line defect length is over about $15\rm nm$, it functions as a perfect channel (quantized conductance) and valley filter (totally polarized); ii) in the diffusive regime, combination effects of backscattering and bulk states assisted intervalley transmission enhance the conductance and suppress the valley polarization; iii) for very long line defect, though the conductance is small, polarization is indifferent to length. Under perpendicular magnetics field, the characters of charge and valley transport are only slightly affected. Finally we discuss the efficiency of transport valley polarized current in a hybrid system.Comment: 6 figure

Existence of solutions for fractional differential equations with three-point boundary conditions at resonance in Rn\mathbb{R}^n

In this paper, by applying the coincidence degree theory which was first introduced by Mawhin, we obtain an existence result for the fractional three-point boundary value problems in $\mathbb{R}^n$, where the dimension of the kernel of fractional differential operator with the boundary conditions can take any value in $\{1,2,\ldots,n\}$. This is our novelty. Several examples are presented to illustrate the result

A VOC Based Approach to Support Virtual Organizations

Employing IT as the key enable technology, virtual organization (VO) is primarily characterized as being a network of independent, geographically dispersed organizations (member organization) providing electronic services via Internet. To align these services effectively, one of the main challenges is to model cooperation in VO and provide correspondent management tools. Here we present a VOC (VO Structure-Organization Resource-Character) approach to model and run VO. VOC consists of three models. VO Structure model describes how VO functions in terms of VO Role (VR), Protocol; Organization Resource model describes potential service providers (potential member organization) capable participate VO. Character Model describes dynamic binding relationship between VO role and member organization. Following the VOC model，a platform supporting the design, administration, and running of VOC is given