Conductance of a finite missing hydrogen atomic line on Si(001)-(2×1)-H

Abstract

We present the results of a calculation of zero-temperature elastic conductance through a finite ''atomic wire'' between Au pads, all supported by a Si͑001͒-͑2ϫ1͒-H surface. The atomic wire consists of a line of dangling bonds which can be fabricated by removing hydrogen atoms by applying voltage pulses to a scanning tunneling microscopy ͑STM͒ tip along one side of a row of H-passivated silicon dimers. Two different line configurations, without and with Peierls distortion, have been considered. We find that the nondistorted line behaves like a single ballistic transmission channel. Conversely, with Peierls distortion present, tunneling occurs through the small resulting energy gap (0.2 eV), leading to inverse decay length of the current of 0.09 Å Ϫ1 . The conductance of the substrate between the pads without the defect line has also been calculated. In this case, tunneling occurs through a much wider energy gap and a larger inverse decay length of 0.41 Å Ϫ1 . These fully three-dimensional atomistic computations represent an application of the electron-scattering quantum-chemistry method which was previously used to calculate the conductance of ''molecular wires'' and of STM junctions with various adsorbates. Compared to molecular wires previously investigated by the same method, the atomic wire studied here exhibits the smallest inverse decay length. ͓S0163-1829͑99͒09123-7͔ PHYSICAL REVIEW B 15 JUNE 1999-II VOLUME 59, NUMBER 24 PRB 59 0163-1829/99/59͑24͒/15910͑7͒/$15.00 15 910

Coherent electron-phonon coupling and polaronlike transport in molecular wires

“…For example, it has been shown both experimentally and theoretically that a Peierls-like transition also occurs in dangling-bond (DB) lines fabricated on the H-passivated Si(001) surface [83][84][85] . More recently, it has been shown theoretically that the injection of a static charge in the bands around the band-gap leads to a distortion of the atomic positions along the line 86 .…”

Dihydride dimer structures on the Si(100):H surface studied by low-temperature scanning tunneling microscopy

“…[1][2][3][4] In the context of molecular electronics, hydrogenated silicon surfaces are also used for atomic-scale patterning of reactive sites 5,6 or conducting lines. [7][8][9][10][11][12] As a result, the atomic structures of hydrogenated Si͑100͒ surfaces have attracted much attention over the past few years. [13][14][15] The adsorption of hydrogen atoms on the Si͑100͒ surface can lead to different surface reconstructions, depending on the surface temperature during the hydrogen adsorption-desorption cycles.…”

Surface-State Engineering for Interconnects on H-Passivated Si(100)

“…The enhanced atom manipulation ability of scanning probes have permitted the creation of quasi 1-D surface states with extraordinary properties. 18,19,[21][22][23][24][25][26] Experimental 18 and theoretical studies 17,21,22,24,25,27 have shown that in the limit of one-atom wide dangling-bond wires, 1-D correlations are very strong and instabilities set in creating electronic gaps in the wire's electronic structure. As recently shown, this has detrimental consequences in the wires' electron-transport properties, 28 reducing the possibilities of dangling-bond wires as alternative interconnects to free-standing 13,14 or embedded 16 nanowires.…”

“…As a remedy for this limitation, Weber et al 16 have recently embedded nanowires on a silicon surface by selectively doping using scanning-probe technology. Previously, an alternative but related approach has been proposed [17][18][19] in which surface electronic states were engineered, taking advantage of the very local nature of silicon bonds. By creating dangling-bond nanowires on silicon surfaces, surface electronic states can be precisely tuned.…”