On the Border Between Matter and Anti-Matter: Nanoscientists Find Long-Sought Majoran

[ScienceRocks]

On the Border Between Matter and Anti-Matter: Nanoscientists Find Long-Sought Majorana Particle


ScienceDaily (Apr. 13, 2012) — Scientists at TU Delft's Kavli Institute and the Foundation for Fundamental Research on Matter (FOM Foundation) have succeeded for the first time in detecting a Majorana particle. In the 1930s, the brilliant Italian physicist Ettore Majorana deduced from quantum theory the possibility of the existence of a very special particle, a particle that is its own anti-particle: the Majorana fermion. That 'Majorana' would be right on the border between matter and anti-matter.

Nanoscientist Leo Kouwenhoven already caused great excitement among scientists in February by presenting the preliminary results at a scientific congress. Today, the scientists have published their research in Science. The research was financed by the FOM Foundation and Microsoft.

Quantum computer and dark matter

Majorana fermions are very interesting -- not only because their discovery opens up a new and uncharted chapter of fundamental physics; they may also play a role in cosmology. A proposed theory assumes that the mysterious 'dark matter', which forms the greatest part of the universe, is composed of Majorana fermions. Furthermore, scientists view the particles as fundamental building blocks for the quantum computer. Such a computer is far more powerful than the best supercomputer, but only exists in theory so far. Contrary to an 'ordinary' quantum computer, a quantum computer based on Majorana fermions is exceptionally stable and barely sensitive to external influences.

Nanowire

For the first time, scientists in Leo Kouwenhoven's research group managed to create a nanoscale electronic device in which a pair of Majorana fermions 'appear' at either end of a nanowire. They did this by combining an extremely small nanowire, made by colleagues from Eindhoven University of Technology, with a superconducting material and a strong magnetic field. "The measurements of the particle at the ends of the nanowire cannot otherwise be explained than through the presence of a pair of Majorana fermions," says Leo Kouwenhoven.

Particle accelerators

It is theoretically possible to detect a Majorana fermion with a particle accelerator such as the one at CERN. The current Large Hadron Collider appears to be insufficiently sensitive for that purpose but, according to physicists, there is another possibility: Majorana fermions can also appear in properly designed nanostructures. "What's magical about quantum mechanics is that a Majorana particle created in this way is similar to the ones that may be observed in a particle accelerator, although that is very difficult to comprehend," explains Kouwenhoven. "In 2010, two different groups of theorists came up with a solution using nanowires, superconductors and a strong magnetic field. We happened to be very familiar with those ingredients here at TU Delft through earlier research." Microsoft approached Leo Kouwenhoven to help them lead a special FOM programme in search of Majorana fermions, resulting in a successful outcome..

Ettore Majorana

The Italian physicist Ettore Majorana was a brilliant theorist who showed great insight into physics at a young age. He discovered a hitherto unknown solution to the equations from which quantum scientists deduce elementary particles: the Majorana fermion. Practically all theoretic particles that are predicted by quantum theory have been found in the last decades, with just a few exceptions, including the enigmatic Majorana particle and the well-known Higgs boson. But Ettore Majorana the person is every bit as mysterious as the particle. In 1938 he withdrew all his money and disappeared during a boat trip from Palermo to Naples. Whether he killed himself, was murdered or lived on under a different identity is still not known. No trace of Majorana was ever found
On the border between matter and anti-matter: Nanoscientists find long-sought Majorana particle

 

[Mr. H.]

I knew a cosmetologist who mixed marjoram with face cream.

 

[waltky]

possum thinks its a good idea - if it works...

Quantum test pricks uncertainty
7 September 2012 - The experiment requires preparing pairs of "entangled" photons, the particles from which light is made

Pioneering experiments have cast doubt on a founding idea of the branch of physics called quantum mechanics. The Heisenberg uncertainty principle is in part an embodiment of the idea that in the quantum world, the mere act of observing an event changes it. But the idea had never been put to the test, and a team writing in Physical Review Letters says "weak measurements" prove the rule was never quite right. That could play havoc with "uncrackable codes" of quantum cryptography.

Quantum mechanics has since its very inception raised a great many philosophical and metaphysical debates about the nature of nature itself. Heisenberg's uncertainty principle, as it came to be known later, started as an assertion that when trying to measure one aspect of a particle precisely, say its position, experimenters would necessarily "blur out" the precision in its speed. That raised the spectre of a physical world whose nature was, beyond some fundamental level, unknowable.

This problem with the act of measuring is not confined to the quantum world, explained senior author of the new study, Aephraim Steinberg of the University of Toronto. "You find a similar thing with all sorts of waves," he told BBC News. "A more familiar example is sound: if you've listened to short clips of audio recordings you realise if they get too short you can't figure out what sound someone is making, say between a 'p' and a 'b'. "If I really wanted to say as precisely as posible, 'when did you make that sound?', I wouldn't also be able to ask what sound it was, I'd need to listen to the whole recording."

The problem with Heisenberg's theory was that it vastly predated any experimental equipment or approaches that could test it at the quantum level: it had never been proven in the lab. "Heisenberg had this intiuition about the way things ought to be, but he never really proved anything very strict about the value," said Prof Steinberg. "Later on, people came up with the mathematical proof of the exact value."

'Full of uncertainty'

 

[waltky]

Supersymmetry theory dealt a blow...

Popular physics theory running out of hiding places
12 November 2012 - Supersymmetry predicts the existence of enigmatic "super particles"

Researchers at the Large Hadron Collider have detected one of the rarest particle decays seen in Nature. The finding deals a significant blow to the theory of physics known as supersymmetry. Many researchers had hoped the LHC would have confirmed this by now. Supersymmetry, or SUSY, has gained popularity as a way to explain some of the inconsistencies in the traditional theory of subatomic physics known as the Standard Model. The new observation, reported at the Hadron Collider Physics conference in Kyoto, is not consistent with many of the most likely models of SUSY.

Prof Chris Parkes, who is the spokesperson for the UK Participation in the LHCb experiment, told BBC News: "Supersymmetry may not be dead but these latest results have certainly put it into hospital." Supersymmetry theorises the existence of more massive versions of particles that have already been detected. Their existence would help explain why galaxies appear to rotate faster than the Standard Model would suggest. Physicists have speculated that as well as the particles we know about, galaxies contain invisible, undetected dark matter made up of super particles. The galaxies therefore contain more mass than we can detect and so spin faster.

Researchers at the LHCb detector have dealt a serious blow to this idea. They have measured the decay between a particle known as a Bs Meson into two particles known as muons. It is the first time that this decay has been observed and the team has calculated that for every billion times that the Bs Meson decays it only decays in this way three times. If superparticles were to exist the decay would happen far more often. This test is one of the "golden" tests for supersymmetry and it is one that on the face of it this hugely popular theory among physicists has failed. Prof Val Gibson, leader of the Cambridge LHCb team, said that the new result was "putting our supersymmetry theory colleagues in a spin".

More BBC News - Popular physics theory running out of hiding places

 

[Mr. H.]

In other news... quantum prick tests uncertainty.

 

[newpolitics]

Interesting stuff!!! Thanks for posting!

 

[udoshia]

Im starting to wonder why people never quote themselves......I mean if you are always saying what someone said before us how can we ever make any progress or ...........have a healthy rumble using our intelect to spar. My mind has been changed many times.........Im proud to say i am always learning but I try and use logic and reason to work it out. of course this can only be done by debate .......and hard to debate unless we all get the facts and form our own opinions although....I did send off for a class in quantom physics and decided I am mathmatically challenged so Ill save the physics discussions for cokctail parties when theory without doing the work sounds ok.

 

[TheOldSchool]

There are so many reports of breakthrough's in science, but why does my vehicle not float and still need wheels???