_ Nanoplasmonics and Nanoelectronics Model Section
Nanoelectronic and plasmonic models, for example, experiments, microwaves and larger metal structures
Researcher and Author: Dr. ( Afshin Rashid)
Note: Since material parameters change significantly with frequency. In particular, this means that model experiments with, for example, microwaves and larger metal structures cannot replace experiments with metal nanostructures at optical frequencies.
The surface charge density fluctuations associated with surface nanoplasmons at the interface between a metal and a dielectric can give rise to strongly enhanced optical near-fields that are spatially confined near the metal surface. Similarly, if the electron gas is confined in three dimensions, such as a small particle, the overall displacement of the electrons relative to the positively charged lattice leads to a restoring force that in turn gives rise to a specific particle-plasmon. Resonance depends on the particle geometry. In suitably shaped particles (usually sharp-pointed), localized charge accumulations associated with strongly enhanced optical fields can occur. Changes in some properties, such as conductivity in nanotransistors and electromagnetic properties in nanowires, can occur on scales of only a few nanometers. The enhancement of surface plasmons in nanoscale structures is called localized surface plasmon resonance. Patterning magnetic materials into arrays of nanoscale dots can lead to a very strong and highly controllable change in the polarization of light when the beam is reflected from the array. This discovery could increase the sensitivity of optical components for telecommunications and biosensor applications. Coupling between light and magnetism in electrical nanostructures Localized Surface Plasmons arise from quantum nanoelectronic interactions. These interactions lead to magneto-optical effects that change properties, such as the polarization axis or the intensity of light. The interactions between light and matter increase at the nanoscale. This is a key motivation in the field of plasmonics, which focuses on the interaction of light with metallic nanostructures to create nanoelectronic devices. In the Localized Surface Plasmon (LSP) electrical nanostructures, a nano-sized metal nanoparticle acts much like an antenna for visible wavelengths. Such antennas have been used in many of our everyday devices, operating at much longer radio and microwave wavelengths, using a phenomenon called surface lattice resonance, in which all the nanoparticles, the tiny antennas, radiate in unison in an array.
The key is to assemble magnetic nanoantennas on a length scale that matches the wavelength of the incoming light. In periodic arrays, the nanoparticles interact strongly with each other, causing collective oscillations. Such behavior has previously been observed in metal nanoparticles.
Conclusion:
Since material parameters change significantly with frequency, this means that model experiments with, for example, microwaves and larger metal structures cannot replace experiments with metal nanostructures at optical frequencies.
Researcher and Author: Dr. ( Afshin Rashid)
Specialized PhD in Nano-Microelectronics