Cotunneling current affected by spin-polarized wire molecules in networked gold nanoparticles

摘要: As a bottom-up approach toward spintronics, network structure of gold nanoparticles connected with spin-polarized wire molecules has been studied. A spinless is prepared as reference system. The an average diameter 4 nm form granules (average 100 nm), which in turn, connect themselves each other to bridge $2\text{ }\ensuremath{\mu}\text{m}$-gap electrodes. Since the charging energy 4-nm nanoparticle amounts 160 meV, it works Coulomb island and conduction through dominated by blockade effect at room temperature. Thermal-activation-type found temperature range 300 K\char21{}30 K, below cotunneling suggested dominate. Important findings reported here are follows: (1) occurs elevated temperatures high $T=30\text{ }\text{K}$ due small size nanoparticles: Nonlinear characteristics featured $I\text{\ensuremath{-}}{V}^{3}$ found, suggesting that number tunnel junctions relevant two. (2) current substantially smaller than network, spin-flip scattering caused localized spins on suppresses process: interpretation supported negative magnetoresistance observed networks.