Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Extraordinary momentum and spin discovered in evanescent light waves

06.03.2014

A team of researchers from the RIKEN Center for Emergent Matter Science (CEMS) in Japan has identified unexpected dynamic properties of a type of light wave called evanescent waves. These surprising findings contrast sharply with previous knowledge about light and photons.

The study carried out in the Quantum Condensed Matter Research Group (CEMS, RIKEN, Japan) led by Dr. Franco Nori is published today in the journal Nature Communications.

Transverse Momentum and Spin in the Evanescent Wave above a Prism

Transverse force and torque on a particle in evanescent field generated from a total internal reflection in a glass prism. These reveal the presence of the transverse momentum and spin in the evanescent wave above the prism.

Credit: RIKEN

Energy, momentum, and angular momentum are the main dynamic characteristics of physical objects. It is well known that light propagating as an electromagnetic wave or photon carries momentum along the direction of the wave's propagation, and that this momentum is independent of polarization. In addition, light can carry an intrinsic angular momentum, called spin, that is proportional to the degree of circular polarization (helicity), and aligned with the propagation direction.

The RIKEN team analysed the momentum and spin of evanescent electromagnetic waves – a type of light waves that travel close to the surface of material objects and whose intensity decreases exponentially, rather than varying sinusoidally, from the interface where they were formed.

Surprisingly, the researchers found that evanescent waves carry momentum and spin components that are orthogonal to the direction of wave propagation. Moreover, the transverse spin turns out to be independent of polarization and helicity, while the transverse momentum is proportional to the wave helicity.

"Such extraordinary properties, revealed in very basic objects, offer a unique opportunity to investigate and observe fundamental physical features, which were previously hidden in usual propagating light and were considered impossible," says Dr. Konstantin Bliokh, first author of the study. "In addition to a detailed theoretical analysis, we propose and simulate numerically four novel experiments for the detection of the unusual momentum and spin properties of evanescent waves via their interaction with small probe particles," he adds.

These results add a new chapter to the physics of momentum and spin of classical and quantum fields, and predict a number of novel light-matter interaction effects involving evanescent waves.

###

For more information please contact:

Juliette Savin
RIKEN
Tel: +81-(0)48-462-1225
Mobile phone: +81-(0)80-8895-2136
Email: pr@riken.jp

Reference:

Extraordinary momentum and spin in evanescent waves
Konstantin Y. Bliokh, Aleksandr Y. Bekshaev, Franco Nori
Nature Communications, 2014 DOI: 10.1038/ncomms4300

About RIKEN

RIKEN is Japan's largest research institute for basic and applied research. Over 2500 papers by RIKEN researchers are published every year in leading scientific and technology journals covering a broad spectrum of disciplines including physics, chemistry, biology, engineering, and medical science. RIKEN's research environment and strong emphasis on interdisciplinary collaboration and globalization has earned a worldwide reputation for scientific excellence.

Website: http://www.riken.jp/en/
Find us on Twitter at @riken_en

About the Center for Emergent Matter Science

The aim of the research carried out at the Center for Emergent Matter Science (CEMS) is to address humanity's energy problems and contribute to building a sustainable society. Taking a pioneering role in the new field of emergent materials science, scientists at CEMS are developing new, more efficient technologies that will enable us to produce energy without putting a burden on the environment, as well as decrease our energy consumption. They achieve this by combining advanced research in physics, chemistry and electronics in order to produce new technology such as highly efficient energy conversion devices and low-consumption electronics.

Website: http://www.cems.riken.jp/en/

Juliette Savin | EurekAlert!

Further reports about: PRISM RIKEN Transverse Momentum physics polarization propagation properties transverse waves

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>