Electric conduction in thin graphite film was tuned by two gate electrodes to clarify how the gate electric field induces electric carriers in thin graphite. The graphite was sandwiched between two gate electrodes arranged in a top and bottom gate configuration. A scan of the top gate voltage generates a resistance peak in ambiploar response. The ambipolar peak is shifted by the bottom gate voltage, where the shift rate depends on the graphite thickness. The thickness-dependent peak shift was clarified in terms of the inter-layer screening length to the electric field in the double-gated graphite film. The screening length of 1.2 nm was experimentally obtained.Comment: 5 pages, 4 figures. To be published in Applied Physics Expres

We experimentally studied the gate voltage dependence of spin transport in multilayer graphene (MLG) using the nonlocal spin detection technique. We found that the spin signal is a monotonically decreasing linear function of the resistance of MLG, which is characteristic of the intermediate interfacial transparency between the MLG and the ferromagnetic electrodes (Co). The linear relation indicates a large spin relaxation length significantly exceeding 8μm. This shows the superiority of MLG for the utilization of the graphite-based spintronic devices.

The size dependence of the resistance switching effect in nanogap junctions was investigated to determine the nature of the local structural changes responsible for the effect. The maximum current, during resistance switching, decreased with the total emission area across the nanogap to an average of 146 μA at a linewidth of 45 nm. This implies that the resistance switching effect stems from changes in the gap width at multiple local sites on the metal surface.