Nanoscale science department

NANOTUBE THEORY       A. Effect of Twisting on Nanotube Electronic Structure Effect of twisting on the properties of a metallic armchair (6,6) nanotube.  Three twisted configurations are shown.  Twisting is found to transform the metallic nanotube to a semiconducting one with a band-gap that varies with the twist angle as shown.   B. Effect of Bending on Nanotube Electronic Structure   Variation of the local density of states (LDOS) along the length of a (6,6) nanotube as a function of the bending angle.    ATOMIC WIRES:  First-principles electronic structure calculations (density functional theory) of the conductance of carbon atom wires bonded to metal electrodes (Metal-Cn-Metal).     Left. Charge density distribution of the metal-C6-metal system. B. Variation of the conductance (in units of 2e2/h) as a function of the number of atoms in the wire. Bottom: A 3D plot of the electrostatic potential of metal-C7-metal (minus the superposition of the potentials of the free C7 wire and the bare electrodes) as a function of position (in atomic units) along the transverse to the wire.  Left. Variation of the conductance (in units of 2e2 /h) as a function of the number of atoms in the wire.  Circles: straight wire, triangles: wire with a 900 bend in the middle of wire. Right: Blue line: difference between the electrostatic potential of the bare metal electrodes biased at 3V and the potential at zero bias.  Red line: difference between the potential of the metal-C7-metal system biased at 3V and the potential of the same system at zero bias, along the wire axis.   [Research home page] [ IBM home page | Order | Search | ContactIBM | Legal ]