Superconductivity of twisted double bi-layer graphene in chiral model

Taking into account the sp -hybridization effect for valence electrons in carbon atoms, a very simple chiral model of graphene was suggested some years ago [1]. This model used as a special order parameter the unitary SU(2) -matrix U with the kink-like (or domain wall) structure for the description of electrons in a mono-atomic graphene sheet. However, later the new graphene physics began since studying twisted multilayer configurations revealing unconventional superconducting properties (twist-tronics) [2]. Within the scope of the chiral model these twisted configurations can be described by the so-called “product ansatz” U = U1U2 ▪ ▪ ▪ Un . As an example, the special case of twisted double bi-layer graphene (TDBG) configuration is studied and the corresponding twist angles, for which the superconductivity takes place, are found.

Hybridization effect on Electrical Conductivity and Thermal Behavior of Epoxy/Carbon Nanotubes and Biosynthesized Silver Nanoparticles Composites

An attempt was made in this work to decorated carbon nanotubes(CNTs) in a polymer matrix using biosynthesized silver nanoparticles (GAgNPs) using Cashew leaves as a reduction agent. The new hybrid epoxy-CNTs+ GAgNPs composites were produced by modified solution-stir-cast method. The microstructure, thermal properties, strength, and electrical conductivity of the produced composites were determined. The electrical conductivity of the epoxy polymer has been enhanced from 5.6x10-13S/cm to 4.80x10-3S/cm for epoxy-0.5%CNTs and 9.1x10-3S/cm epoxy-0.5%CNTs-0.5%GAgNPs. GAgNPs was effective used to improve the strength of conducting epoxy-CNTs for electronic devices. The addition of CNTs and GAgNPs to epoxy increases the glass transition temperature. It was established that GAgNPs can be promising materials to enhanced thermal conductivity, strength, electrical conductivity of epoxy-CNTs and recover the potential reduction for electronic devices application.