Generation of Ordered Atomic Gold Nanowires Via Tip-Enhanced Terahertz Field

We report an innovative way of generating gold single-atom-wide nanowires through a purely optical method, using tip-enhanced terahertz (THz) radiation in a scanning tunneling microscope. Our finding highlights <i>ordered</i> nanostructures could be fabricated by ultrafast THz pulses. The nature of the single-atom gold nanowires is verified by scanning tunneling spectroscopy from the dispersion of 1D confined states. Furthermore, we observe a previously unknown surface (2x2) superlattice on Au(111), which is overlaid on the herringbone reconstruction, accompanying the nanowires. The formation mechanism is not yet fully understood but plausible scenarios will be discussed.