Scanning Tunneling Nanoplasmonics
- Reference number
- FFL09-0113
- Start and end dates
- 110101-171231
- Amount granted
- 9 700 000 SEK
- Administrative organization
- Chalmers University of Technology
- Research area
- Materials Science and Technology
Summary
Objectives: The project aims at introducing scanning tunneling microscopy / spectroscopy (STM/STS) into the nanoplasmonics research to develop novel nanostructured optically active materials with the groundbreaking properties, based on plasmonic characteristics of metallic and metal-dielectric hybrid nanoscale systems. The goal is to study fundamentals of such systems with the ultimate resolution of the STM/STS combined with in situ optical spectroscopy and to apply this knowledge for the design of novel magneto-plasmonic (spin-plasmonic) materials and label-free ultra-high-sensitive biomolecular and materials detectors. Work plan & expected results: task 1: using UHV STM as an imaging tool for the design of nanoplasmonic materials with sub-nm precision. This includes acquiring and bringing to the routine operation the custom-designed variable-temperature UHV STM with the possibility of in situ optical spectroscopy. This will result in real-space and spectroscopic study of the spin-plasmonics nanoscale systems, and development of the tunable nanoplasmonic materials and optical sensing, for example, of the enzyme-like catalytic processes, supported by the metal-organic coordination networks. task 2: using UHV STM as a novel instrument for the ultimate spatial resolution of the nanoplasmonic modes: simultaneous topographic and near-field characterization of plasmonic structures for nanophotonics research.
Popular science description
When visible light interacts with metallic particles of nanoscopic size (1 nanometer = 10(-9) meters) interesting effects can be observed. For example, the changing colors of the stained glass goblets that were manufactured in the Roman Empire or spectacular color motifs that can be found in medieval church windows are the products of such light-matter interaction – i.e., strong modification of light by nanosized metallic particles. The origin of such interaction is that light experiences strong absorption and scattering since it can couple to the collective oscillations of the electrons in metal nanoparticles (such collective oscillations are called ‘localized surface plasmons’). Another feature of such coupling is that around irradiated nanostructures strongly enhanced electromagnetic fields are induced, which are extremely sensitive to the change in the nanoparticle direct surroundings. In recent years researchers learned to control the interaction of light with nanostructures by synthesizing them in solutions or manufacturing them on supports (like glass slides). In such carefully crafted nanostructures one can control light-induced electronic oscillations, and new and unusual optically active materials can be created, like flat lenses to image nanoscale objects, electromagnetic ‘invisibility’ cloaks or biosensors able to detect single molecules. Presented project will explore the underlying principles of light-matter interaction by using scanning tunnelling microscopy. This Nobel-prize winning technique was invented in the 80es and essentially brings sharp metal tip very close to the investigated surface. If the voltage is applied between tip and the sample, so called ‘tunneling’ current can flow through the gap between the tip and the surface. If in the same time the tip is moved across the surface, this current changes so that single-atom or single-molecule ‘bumps’ can be detected. This technique can also study the interaction of light with small structures on the surface with the same very high resolution. Eventually, valuable information that can be obtained with such technique by studying arrangements of very small metallic and metal-dielectric structures will be transformed into biomedical and materials sensors and devices for optical manipulation and storage of information.