Conductance of Ag atoms and clusters on Ag(111): Spectroscopic and time‐resolved data

Abstract

The evolution of the electronic structure of linear atomic Ag chains on Ag(111) has been explored atom by atom using lowtemperature scanning tunnelling microscopy and spectroscopy. Electronic states confined to the linear chains are well described within a particle-in-a-box model. The evolution of an unoccupied Ag monomer resonance during the synthesis of an Ag dimer reveals that the Ag-Ag interaction is predominantly direct owing to the large spatial extension of p wave functions of the adsorbed atoms. The hopping dynamics of a single Ag atom adsorbed on Ag(111) have been monitored by time-resolved two-level conductance fluctuations of the tunnel junctions. Effective temperatures of the junction and diffusion barrier heights in the presence of the tip were extracted from a voltage-dependent analysis of the fluctuation rate.

Channel saturation and conductance quantization in single-atom gold constrictions

“…Realization of electronic devices based on atomic-sized metal or metal-molecule hybrid systems 1-4 requires a fundamental understanding of conditions under which conductance quantization prevails, 5 their electronic structure and regulation of electron transmission behavior, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] and their mechanical stability against disruptive forces of entropic thermal fluctuations. [20][21][22][23] In addition, positioning and manipulation of individual atoms requires fundamental understanding of the operative forces, [24][25][26][27] and the ability to measure them.…”

Mechanics of quantum and Sharvin conductors

“…4 shows a zoom-in view of the plot at lower values of . Figure 4 shows that these four sharply defined levels transitions into a diffuse 8 band with an average value of ~0.168 nm and this crossover occurs at a conductance value of . The diameter corresponding to this conductance value is equal to 1.45 nm (using Sharvin formula; discussed later).…”

Precise atom manipulation through deep reinforcement learning

“…For metal adatoms on close-packed metal (111) surfaces, the fcc and hcp hollow sites are generally the most energetically favorable adsorption sites. 39,40,45 For Ag adatoms on the Ag(111) surface, the energy of fcc sites is found to be ¡10 meV lower than hcp sites in theory 39 and STM manipulation experiments. 40 Here the distribution of manipulation-induced adatom movements from the training data shows that Ag adatoms can occupy both fcc and hcp sites, evidenced by the six peaks ∼ a √ 3 = 0.166 nm from the origin (Fig.…”

“…For Ag on Ag(111) surfaces, the fcc (face-centred cubic) and hcp (hexagonal close-packed) hollow sites are the most energetically favorable adsorption sites. 39,40 From the geometry of the adsorption sites, the error ε is limited to ranges from 0 nm to a √ 3 depending on the target position. Therefore, the episode is considered successful and terminates if the ε is lower than a √ 3 .…”

“…(b) The atom manipulation goal is to bring the adatom as close to the target position as possible. For Ag on Ag(111) surfaces, the fcc (face-centred cubic) and hcp (hexagonal close-packed) hollow sites are the most energetically favorable adsorption sites 39,40. From the geometry of the adsorption sites, the error ε is limited to ranges from 0 nm to a…”