Electron Quantization in Broken Atomic Wires

TL;DR

This study uses STM and spectroscopy to observe electron quantization in atomic-scale gold wires on silicon, revealing 1D quantum well states, conductance oscillations, and challenging previous assumptions about adatom doping roles.

Contribution

It demonstrates atomic-scale electron quantization in self-assembled gold wires, highlighting the role of adatoms as scatterers rather than dopants, and introduces a platform for 1D quantum studies.

Findings

Observation of 1D quantum well states with inverse-length-square energy dependence.

Detection of quantum oscillations in conductance at the Fermi level.

Adatoms act as strong scatterers, not dopants, in atomic wires.

Abstract

We demonstrate using scanning tunneling microscopy and spectroscopy the electron quantization within metallic Au atomic wires self-assembled on a Si(111) surface and segmented by adatom impurities. The local electronic states of wire segments with a length up to 10 nm are investigated as terminated by two neighboring Si adatoms. One dimensional (1D) quantum well states are well resolved by their spatial distributions and the inverse-length-square dependence in their energies. The quantization also results in the quantum oscillation of the conductance at the Fermi level. These results deny the dopant role of the adatoms assumed for a long time but indicate their strong scattering nature. The present approach provides a new and convenient platform to investigate 1D quantum phenomena with atomic precision.