Atomically flat single-crystalline gold nanostructures for plasmonic nanocircuitry

TL;DR

This paper presents a method to create atomically flat, single-crystalline gold nanostructures that enable high-definition plasmonic nanocircuitry with improved optical properties and reproducibility.

Contribution

The authors demonstrate the use of large chemically grown single-crystalline gold flakes as a substrate for precise nanofabrication, overcoming limitations of multi-crystalline gold layers.

Findings

Ultrasmooth, high-definition gold nanostructures with superior optical properties.

Reproducible nano-sized features over micrometer scales.

Potential to realize high-definition plasmonic nanocircuitry.

Abstract

Deep subwavelength integration of high-definition plasmonic nanostructures is of key importance for the development of future optical nanocircuitry for high-speed communication, quantum computation and lab-on-a-chip applications. So far the experimental realization of proposed extended plasmonic networks consisting of multiple functional elements remains challenging, mainly due to the multi-crystallinity of commonly used thermally evaporated gold layers. Resulting structural imperfections in individual circuit elements will drastically reduce the yield of functional integrated nanocircuits. Here we demonstrate the use of very large (>100 micron^2) but thin (<80 nm) chemically grown single-crystalline gold flakes, which, after immobilization, serve as an ideal basis for focused-ion beam milling and other top-down nanofabrication techniques on any desired substrate. Using this methodology we obtain high-definition ultrasmooth gold nanostructures with superior optical properties and reproducible nano-sized features over micrometer length scales. Our approach provides a possible solution to overcome the current fabrication bottleneck and to realize high-definition plasmonic nanocircuitry.