A landmark experiment on wave interference from the early 1800s is revisited using gold nanoparticles
In the eighteenth century, scientists faced a conundrum: is light a wave or a particle? One of strongest pieces of evidence to support the ‘wave view’ — the landmark double-slit experiment — was reported in 1804 by the scientist Thomas Young. Young passed coherent light through two closely spaced slits and observed a set of interference fringes, a result that occurs with wave phenomena like sound or water. This observation became the basis for the modern wave theory of light.
Example of the energy flow and optical vortices found around closely spaced gold nanoparticles. The effects resemble the field lines seen in Young’s slit experiments.
Copyright : 2014 A*STAR Data Storage Institute
Two hundred years later, Arseniy Kuznetsov and co-workers from the A*STAR Data Storage Institute, together with collaborators in Australia, Singapore, the United Kingdom and Russia, have performed an experiment analogous to Young’s experiments but using nanoscale objects (1). The team studied the light scattering in the visible and near-infrared wavelength regions from a cluster of two or three closely spaced gold plasmonic nanoparticles. They observed interference and resonance effects that resemble those seen in Young’s experiments.
In particular, while studying a trimer system consisting of three discrete metallic nanodisks of about 145 nanometers in diameter and 60 nanometers thick, the team found evidence for the presence of near-field, subwavelength-sized optical vortices and the circulation of electromagnetic energy (see image). This finding is very similar to what occurs to the energy flow pattern in a Young-type experiment performed with three slits.
One of the key issues in nanoplasmonics is the interaction between metallic nanoparticles at the nanoscale. “Even if the separation between two or multiple non-periodically arranged nanoparticles is of the order of wavelength, their interaction can be strong enough to change their scattering and absorption properties,” notes Kuznetsov. “This can be explained by the peculiarities of the Poynting vector (energy) flow around the nanoparticles and formation of optical vortices, which produce a pattern of field lines similar to Young’s classic experiment.”
The team’s findings, says Kuznetsov, not only expand our fundamental understanding of how light interacts with nanoclusters of metallic particles, but have both theoretical and practical applications. “They may also prove useful for applications such as improved solar cells and plasmonic biosensors.” However, their most remarkable application, he suggests, may be in the emerging area of nanoantennas.
In the future, the team is aiming to study the resonant properties and interactions of nanoparticles made from nonmetallic materials. In particular, they plan to investigate high-refractive index dielectric materials such as silicon, which, unlike metallic particles, do not suffer from high optical losses.
The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute
Rahmani, M., Miroshnichenko, A. E., Lei, D. Y., Luk’yanchuk, B., Tribelsky, M. I. et al. Beyond the hybridization effects in plasmonic nanoclusters: Diffraction-induced enhanced absorption and scattering. Small 10, 576–583 (2013).
New Boost for ToCoTronics
23.05.2019 | Julius-Maximilians-Universität Würzburg
The geometry of an electron determined for the first time
23.05.2019 | Universität Basel
Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.
The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...
Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...
With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.
Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...
'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.
However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...
Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future
When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
23.05.2019 | Materials Sciences
23.05.2019 | Materials Sciences
23.05.2019 | Physics and Astronomy