Double-gate single-electron transistors (SETs) were fabricated by chemical assembling using electroless gold-plated nanogap electrodes and chemisorbed chemically synthesized gold nanoparticles. The fabricated SET showed periodic and stable Coulomb oscillations under application of voltages of both gates. The sole SET also exhibited all two-input logic operations-XOR, XNOR, NAND, OR, NOR, and AND-with an on/off ratio of 10(2). This demonstrates the potential of chemical assembling to give highly stable SETs exhibiting all logic operations.

We report inelastic electron tunneling spectroscopy (IETS) of a C8 alkanethiol self-assembled monolayer using a scanning tunneling microscope (STM). High-resolution STM IETS spectra show clear features of the C-H bending and C-C stretching modes in addition to the C-H stretching mode, which enables a precise comparison with previously reported vibrational spectroscopy, especially electron energy loss spectroscopy data. Intensity variation of vibrational peaks with tip position is discussed with the STM IETS detection mechanism.

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We investigate inelastic electron tunneling spectroscopy (IETS) for alkanethiol self-assembled monolayers (SAM) with a scanning tunneling microscope and compare it to first-principles calculations. Using a combination of partial deuteration of the molecule and high-resolution measurements, we identify and differentiate between methyl (CH3) and methylene (CH2) groups and their symmetric and asymmetric C-H stretch modes. The calculations agree quantitatively with the measured IETS in producing the weight of the symmetric and asymmetric C-H stretch modes while the methylene stretch mode is largely underestimated. We further show that inelastic intermolecular scattering is important in the SAM by plotting the theoretical current densities.