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Using dielectric materials as efficient EM radiators and receivers can scale down these antenna's to the chip level, reducing both weight and power consumption. The infamous internet-of-things one step closer. But could we also transmit power this way?? "In dielectric aerials, the medium has high permittivity, meaning that the velocity of the radio wave decreases as it enters the medium," said Dr Dhiraj Sinha, the paper's lead author. "What hasn't been known is how the dielectric medium results in emission of electromagnetic waves. This mystery has puzzled scientists and engineers for more than 60 years." The researchers determined that the reason for this phenomenon is due to symmetry breaking of the electric field associated with the electron acceleration The researchers found that by subjecting the piezoelectric thin films to an asymmetric excitation, the symmetry of the system is similarly broken, resulting in a corresponding symmetry breaking of the electric field, and the generation of electromagnetic radiation.

It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its pertinent optical vorticity and phase singularities began to come into widespread use in science and technology. We have now shown experimentally how OAM and vorticity can be readily imparted onto radio beams. Our results extend those of earlier experiments on angular momentum and vorticity in radio in that we used a single antenna and reflector to directly generate twisted radio beams and verified that their topological properties agree with theoretical predictions. This opens the possibility to work with photon OAM at frequencies low enough to allow the use of antennas and digital signal processing, thus enabling software controlled experimentation also with first-order quantities, and not only second (and higher) order quantities as in optics-type experiments. Since the OAM state space is infinite, our findings provide new tools for achieving high efficiency in radio communications and radar technology.

and how can we use this?

A new type of structure for converting red light into blue has been unveiled by researchers in the US. Known as frequency doubling or second-harmonic generation (SHG), the conversion involves "nanocups", which are tiny, artificially designed 3D structures. SHG is used in light sources and in metrology applications - and the researchers believe that the new structures could be adapted to achieve frequency doubling in parts of the electromagnetic spectrum where it is currently not possible.

"...scientists in Germany have built a device that can effectively make objects invisible to sound waves. The performance of the acoustic "invisibility cloak" exceeds that of existing electromagnetic devices and could open up new ways of manipulating waves, including the development of shields against seismic waves."

shit.... they are a few months ahead of us it seems ... :-( what is the impact on our ariadna??

The atom may not be a planetary system, but under specific circumstances it can behave like one. That is the curious finding of physicists in Austria and the US, who have confirmed a 1994 prediction that, in the presence of an applied electromagnetic field, electrons in very highly energized atomic states should behave like the Trojan asteroids of Jupiter.

Bohr's model finally not so wrong?

The principle behind that is Nantenna.

this is fantastic!!!! waiting of somebody to make this happen since years The size of the gap is critical because it creates an ultra-fast tunnel junction between the rectenna's two electrodes, allowing a maximum transfer of electricity. The nanosized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before their electrical current reverses and they try to go back. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to a unidirectional current. Impressively, the rectennas, because of their extremely small and fast tunnel diodes, are capable of converting solar radiation in the infrared region through the extremely fast and short wavelengths of visible light - something that has never been accomplished before. Silicon solar panels, by comparison, have a single band gap which, loosely speaking, allows the panel to convert electromagnetic radiation efficiently at only one small portion of the solar spectrum. The rectenna devices don't rely on a band gap and may be tuned to harvest light over the whole solar spectrum, creating maximum efficiency. Through atomic layer deposition, Willis has shown he is able to precisely coat the tip of the rectenna with layers of individual copper atoms until a gap of about 1.5 nanometers is achieved. The process is self-limiting and stops at 1.5 nanometer separation The size of the gap is critical because it creates an ultra-fast tunnel junction between the rectenna's two electrodes, allowing a maximum transfer of electricity. The nanosized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before their electrical current reverses and they try to go back. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to a unidirectional current. Impressively, the rectennas, because of th

See Also: Matter & Energy Nanotechnology Optics Physics Materials Science Graphene Organic Chemistry Reference White gold Electromagnetic radiation Nanomedicine Nanoparticle Any use for the smell project? "We have demonstrated resonant antenna-enhanced single-particle hydrogen sensing in the visible region and presented a fabrication approach to the positioning of a single palladium nanoparticle in the nanofocus of a gold nanoantenna,"

An overview is given on the field of the terahertz-frequency electromagnetic waves, their properties and emerging applications. Some widespread sources with their advantages and drawbacks are presented; an emphasis is placed on the parametric generation s

Electromagnetic analysis of cylindrical invisibility cloaks and the mirage effect

article written a bit as if they had invented rectennas ... they are used since the 60s (Brown powered a small helicopter via 2.45 GHz ... and Kaya-san has showed wireless power transmission via advanced rectenna's at almost every SPS conference since 20 years ...

Here you go. You can now scrap Lisa altogether. Who's going to tell Pacome?

Awesome and exciting stuff indeed! The data pinpoint the time when inflation occurred - about 10E-37 seconds into the Universe's life - and its temperature at the time, corresponding to energies of about 10E16 gigaelectronvolts, says cosmologist Michael Turner of the University of Chicago. That is the same energy at which three of the four fundamental forces of nature - the weak, strong and electromagnetic force - are expected to become indistinguishable from one another in a model known as the grand unified theory. I expect more fundamental physics insights to come out of this in the future. A full-sky survey from space may still be an interesting addition to the measurement capabilities, so I would not rule out LISA all together I guess...

Interesting overview paper by Massa from Trient on reconfigurable metamaterials … makes me wonder if it is time for us to look closer into it or already too late …

Physicists have found a radical new way to confine electromagnetic energy without it leaking away, akin to throwing a pebble into a pond with no splash. The theory could have broad ranging applications from explaining dark matter to combating energy losses in future technologies.

I think (but am not sure) that is related to a topic that Dirk Bouwmeester's group at Leiden University works on for a while now: "Linked and knotted beams of light" http://irvinelab.uchicago.edu/papers/nphys1056.pdf

Quantum Cascade Lasers are rising in the mid-infrared region, the so-called fingerprint zone of the electromagnetic spectrum for a whole bunch of chemical species that we are most of times interested in sensing. One more sign of the underlying importance of this technology comes just by seeing NSF, USHS, Naval Air Command and NASA as the main monetary contributors to this research.

antihydrogen propulsion...?

didn't roger write an assessment of antimatter propulsion when he was in the ACT?

yeah the problem is the amount of antimatter you can get and more specifically how to trap it. I found that you would need around one gram to go to the outer Solar System. So we are far from that, but finding an efficient way to trap it, with an electromagnetic trap rather than solid walls is a first step !

A very nice model how things should not be done :D

Luzi we miss you .... :-)

what the heck is this?? sounds really strange but highly interesting to me ....

can we use this for energy transmission?

read it now more carefully and the answer is probably no ...