A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory calculations.Unlike their flat counterpart-zigzag-edged carbon nanoribbons,which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations,namely spin-selective semiconductors,metals,semimetals,quasi-half-metals,and half-metals.To the best of our knowledge,this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric field.In addition,we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains,and found that they are 13% and 17% at the Fermi level,respectively,suggesting that ZCNS can be an effective spin filter.
Lin LaiJing LuLu WangGuangfu LuoJing ZhouRui QinYu ChenHong LiZhengxiang GaoGuangping LiWai Ning MeiYutaka MaedaTakeshi Akasakaand Stefano Sanvito
Symmetric tapered dielectric structures in metal have demonstrated applications such as the nanofocusing of surface plasmon polaritons,as well as the waveguiding of V-channel polaritons.Yet the fabrication of smooth-surfaced tapered structure remains an obstacle to most researchers.We have successfully developed a handy method to fabricate metal-sandwiched tapered nanostructures simply with electron beam lithography.Though these structures are slightly different from conventional symmetric V-shaped structures,systematic simulations show that similar functionality of surface plasmon polariton nanofocusing can still be achieved.When parameters are properly selected,wavelengthselective nanofocusing of surface plasmon polaritons can be obtained.
