Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Metamaterials shake up electrons

29.09.2008
New man-made materials could produce unique chaotic motion in electron beams

A team at the RIKEN Advanced Science Institute in Wako has predicted that man-made structures called metamaterials could produce instabilities in electron beams (1). The effect could provide new methods for generating and amplifying optical signals.

Metamaterials are often known as left-handed media (LHM) because they break the right-hand rule of electromagnetism. This means that the ‘envelope’ of a wave—created by changes in wave height—in LHM can move in the opposite direction to the wave’s overall motion. This is expected to produce phenomena similar to backward wave oscillators, which are common sources of microwave radiation.

“Any system that contains two oppositely directed fluxes of information can be unstable if the coupling between the information carriers (waves and electrons in our case) is strong enough,” explains RIKEN scientist Yuriy Bliokh, also at Technion-Israel Institute of Technology in Haifa.

The coupling between carriers in LHM is provided by Cherenkov radiation—a type of radiation emitted when a charged particle passes through an insulator at a speed faster than the speed of light in the insulator. It is responsible for the blue glow in nuclear reactors, and propagates from a particle beam just like the wake from a moving ship.

In LHM, Cherenkov radiation moves backwards, providing strong feedback for particles moving behind. In particular, two electron beams side-by-side could excite each other via their Cherenkov radiation, producing unstable, chaotic motion in the beams.

To investigate these effects, Bliokh and RIKEN co-workers Sergey Savel’ev, also at Loughborough University, UK, and Franco Nori, also at the University of Michigan, USA, developed a model which solves the equations of motion for two electron beams passing through LHM, and calculates the total electric field generated. "Small perturbations in the beam density were introduced to represent fluctuations that can occur in the real world," says Savel'ev.

The small perturbations developed into large instabilities, causing the beam to excite itself. "The behavior resembles beam instabilities that have been discovered in both plasma physics and microwave electronics," says Nori, and could have several applications if a suitable LHM can be realized in the laboratory.

“From my point of view, the most interesting applications would be in the short-wavelength (infrared, visible light) range, because there are already so many devices in the microwave frequency band,” says Bliokh. “This effect could provide tunable sources of regular or stochastic radiation. Also, when the beam current is low, the instability is not developed and the system could be used as an amplifier.”

1. Bliokh, Y.P., Savel’ev, S. & Nori, F. Electron-beam instability in left-handed media. Physical Review Letters 100, 244803 (2008).

Saeko Okada | ResearchSEA
Further information:
http://www.rikenresearch.riken.jp/research/539/
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

A new dead zone in the Indian Ocean could impact future marine nutrient balance

06.12.2016 | Earth Sciences

Significantly more productivity in USP lasers

06.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>