We consider the Kane-Mele model supplemented by a Hubbard U term. The phase diagram is mapped out using projective auxiliary field quantum Monte Carlo simulations. The quantum spin liquid of the Hubbard model is robust against weak spin-orbit interaction, and is not adiabatically connected to the spin-Hall insulating state. Beyond a critical value of U>U(c) both states are unstable toward magne...

The structural and electronic properties of the hydrogenated porous graphene nanoribbons were studied by using density functional theory calculations. The results show that the hydrogenated porous graphene nanoribbons are energetically stable. The effects of ribbon type and ribbon width on the electronic properties of these nanoribbons were investigated. It was found that both armchair and zigz...

Exploitation of plant lignocellulosic biomass is hampered by our ignorance of the molecular basis for its properties such as strength and digestibility. Xylan, the most prevalent non-cellulosic polysaccharide, binds to cellulose microfibrils. The nature of this interaction remains unclear, despite its importance. Here we show that the majority of xylan, which forms a threefold helical screw in ...

The controllable fabrication of self-scrolling SiGe/Si/Cr helical nanoribbons on Si(111) substrates is investigated. The initial lateral etching profile of the Si(111) substrates shows a 2-fold rotational symmetry using 4% ammonia solution, which provides guidance for initial scrolling of one-end-fixed nanoribbons to form helical structures. The chirality of the SiGe/Si/Cr helices with isotropi...

We describe the design and synthesis of a new graphene ribbon architecture that consists of perylenediimide (PDI) subunits fused together by ethylene bridges. We created a prototype series of oligomers consisting of the dimer, trimer, and tetramer. The steric congestion at the fusion point between the PDI units creates helical junctions, and longer oligomers form helical ribbons. Thin films of ...

The edge states of two-dimensional time-reversal topological insulators support a perfect helical conductance on wide ribbons due to the absence backscattering. Here, we study changes in transport properties insulator nanoribbons by introducing constriction along ribbon. This setup allows hybridize, leading reflections at ends constriction. We find that electronic running one can be reflected b...

Defect-free one-handed contracted helical tubular ladder polymers with a π-electron-rich cylindrical cavity were synthesized by alkyne benzannulations of the random-coil precursor containing 6,6′-linked-1,1′-spirobiindane-7,7′-diol-based chiral monomer units. The resulting tightly-twisted showed remarkably high enantioseparation abilities toward variety hydrophobic aromatics point, axial, and p...

Spiroplasmas are small helical bacteria without rigid walls. They have a cytoskeleton in the form of a flat ribbon that runs the length of the cell. In an ordinary liquid medium, a cell spins about its long axis, but it does not translate. In a gel-like medium, containing a viscous agent like methylcellulose, it moves rapidly in a direction parallel to its long axis. Here I suggest how a cytosk...