Tailoring the Electronic Properties of Gold Chains on Silicon

For observing the exotic properties predicted for electrons in one-dimension, it is desirable to have one-dimensional solids with tunable electronic properties. We have explored gold atom chains on stepped silicon surfaces using a combination of scanning tunneling microscopy and angle-resolved photoemission. Vicinal Si(111) surfaces with odd Miller indices, such as Si(335), Si(557), Si(553), Si(775), and others, form regular chain structures upon deposition of a fraction of a monolayer of gold. They exhibit metallic bands with nearly one-dimensional Fermi surfaces. From a tight binding fit to the data we find that band filling and inter-chain coupling can be varied systematically, for example from an intra-/inter-chain coupling ratio of 10:1 to >70:1. These self-assembled atomic chains represent a highly-flexible class of solids that approach the one-dimensional limit.[1] [1] Accepted for publication in Physical Review B.