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Scooped by Dr. Stefan Gruenwald!

Flashes of light in particularly sensitive quantum states can be transmitted through the atmosphere

Flashes of light in particularly sensitive quantum states can be transmitted through the atmosphere | Amazing Science |

New prospects for secure data traffic: Flashes of light in particularly sensitive quantum states can be transmitted through the atmosphere. Erlangen-based physicists have sent bright pulses in sensitive quantum states through the window of a technical services room on the roof of the Max Planck Institute for the Science of Light to a building of the University Erlangen-Nürnberg.

It could be difficult for the NSA to hack encrypted messages in the future – at least if a technology being investigated by scientists at the Max Planck Institute for the Science of Light in Erlangen and the University Erlangen-Nürnberg will be successful: quantum cryptography. The physicists are now laying the foundation to make this technique, which can already be used for the generation of secret keys, available for a wider range of applications. They are the first scientists to send a pulse of bright light in a particularly sensitive quantum state through 1.6 kilometers of air from the Max Planck Institute to a University building. This quantum state, which they call squeezed, was maintained, which is something many physicists thought to be impossible. Using flashes of bright light for quantum communication through the atmosphere would have several advantages compared to the technique usually used today: it allows the photon packets to be transmitted in sunlight, something that is challenging with individual photons. Moreover, the receivers required for this are already presently in use for optical telecommunication via fibre optics and also via satellite.

Eavesdropping on a message protected by quantum cryptography cannot be done without being noticed. This is because quantum physics prevents a spy from reading a key which is encoded by specific quantum states without influencing these states. This can be exploited in a clever procedure for exchanging the key with which the data is encrypted, so that an unwelcome listener is not only detected, but is also prevented from accessing the information.

The quantum-protected communication is a fragile thing, however, and easily disturbed. All the more remarkable is the work of the Erlangen-based scientists working with Gerd Leuchs, Director at the Max Planck Institute for the Science of Light and professor at the University Erlangen-Nürnberg: "We have now succeeded in transmitting a flash of light, namely a pulse which contains many photons, through the atmosphere in a particularly sensitive quantum state," says Christian Peuntinger, who played an important role in the project. He and his colleagues sent a photon packet in a straight line from the roof of the Max Planck Institute in Nuremberg to the building of the University Erlangen-Nürnberg some 1.6 kilometers away. "This even works in broad daylight," says Christian Peuntinger.

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Novel forms of superconductivity: Two-dimensional electron liquids

Novel forms of superconductivity: Two-dimensional electron liquids | Amazing Science |

Truly two-dimensional objects are rare. Even a thin piece of paper is trillions of atoms thick. When physicists do succeed in producing 2D systems, quantum interactions can lead to new phenomena and Nobel prizes. Two examples: graphene—-single-atom-thick sheets of carbon atoms—-has unique mechanical, electrical, and optical properties; and two-dimensional electron gases (2DEG)—-planar collections of electrons supported at the interface between certain semiconductors such as gallium arsenide—-allow the observation of such emergent behaviors as the quantum Hall effect and the spin Hall effect.

A relatively new frontier for studying 2D matter is provided by planar collections of electrons at the surface of transition-metal-oxide (TMO) materials, in which high electron densities give rise to interactions that are stronger than in semiconductors. Consequently it is more accurate to refer to the TMO electron ensemble as a 2D liquid rather than as a 2D gas. Scientists hope to find exotic emergent phenomena in these high-density, highly-interactive electron environments.

One of the leaders in this effort is James Williams, a new fellow at the Joint Quantum Institute (JQI), where he is also an assistant professor of physics at the University of Maryland. Before he left Stanford University, Williams and his colleagues performed tests on a thin sample of strontium titanate (STO) covered over with an electrolyte gel, a material in which negative and positive ions dissociate (saltwater is a common electrolyte: Na+ and Cl- ions come apart in a water solution). Their results appear in the journal Nature Physics.

Their new experimental results are reported online in the journal Nature Physics on August 31, 2014. The authors speculate that this behavior is consistent with (but not yet proof of) of novel superconductivity, one candidate of which is a p-wave superconductor . More research needs to be done before this speculation is given a strong footing. In conventional, or s-wave superconductivity, the pairs of electrons (Cooper pairs) that constitute a zero-resistance current, are spherical in shape. In p-wave superconductivity, the pairs would look more like miniature dumbbells festooned with additional lobes.

P-wave superconductivity has not been unambiguously seen yet since the anatomy of the electron pairs is difficult to establish. But the search has generated much interest. This is because theorists believe the p-wave materials could support the existence of Majorana particles (named for physicist Ettore Majorana), which are expected to have strange properties, such as being their own antiparticles.

group 6a's curator insight, October 27, 2014 4:08 AM

Use strontium titanate to study the two-dimensional electron liquids form of superconductivity

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Layered graphene sandwich for next generation electronics

Layered graphene sandwich for next generation electronics | Amazing Science |
Sandwiching layers of graphene with white graphene could produce designer materials capable of creating high-frequency electronic devices, University of Manchester scientists have found.

Writing in Nature Nanotechnology, the researchers have demonstrated how combining the two-dimensional materials in a stack could create perfect crystals capable of being used in next generation transistors.

Hexagonal boron nitride (hBN), otherwise known as white graphene, is one of a family of two-dimension materials discovered in the wake of the isolation of graphene at the University in 2004. Manchester researchers have previously demonstrated how combining 2D materials, in stacks called heterostructures, could lead to materials capable of being designed to meet industrial demands.

Now, for the first time, the team has demonstrated that the electronic behaviour of the heterostructures can be changed enormously by precisely controlling the orientation of the crystalline layers within the stacks.

The researchers, led by University of Manchester Nobel laureate Sir Kostya Novoselov, carefully aligned two graphene electrodes separated by hBN and discovered there was a conservation of electron energy and momentum.

The findings could pave the way for devices with ultra-high frequencies, such as electronic or photovoltaic sensors.

The research was carried out with scientists from Lancaster and Nottingham Universities in the UK, and colleagues in Russia, Seoul and Japan.

Professor Laurence Eaves, a joint academic from the Universities of Manchester and Nottingham, said: ""This research arises from a beautiful combination of classical laws of motion and the quantum wave nature of electrons, which enables them to flow through barriers.

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Google plans to build their very own superconductor-based quantum computer

Google plans to build their very own superconductor-based quantum computer | Amazing Science |

Hartmut Neven, Director of Engineering for the Quantum Artificial Intelligence team at Google said the team is launching a hardware initiative to design and build new quantum information processors based on superconducting electronics.

John Martinis and his team at UC Santa Barbara will join Google in this initiative. Martinis and his group have been building superconducting quantum electronic components of very high fidelity. In April, they announced in Nature that they had developed a superconducting five-qubit array with “an average single-qubit gate fidelity of 99.92 per cent and a two-qubit gate fidelity of up to 99.4 per cent.”

“With this new integrated hardware group,  Google’s Quantum AI team will now be able to implement and test new designs for quantum optimization and inference processors based on recent theoretical insights as well as their learnings from the D-Wave quantum annealing architecture,” Neven said.

“We will continue to collaborate with D-Wave scientists and to experiment with the ‘Vesuvius’ machine at NASA Ames, which will be upgraded to a 1000 qubit ‘Washington’ processor.”

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Schrödinger's cat caught on quantum film using quantum entanglement

Schrödinger's cat caught on quantum film using quantum entanglement | Amazing Science |

The patron animal of quantum theory poses for a unique portrait in which the camera and the sitter don't share a single photon – except by entanglement.

Information is central to quantum mechanics. In particular, quantum interference occurs only if there exists no information to distinguish between the superposed states. The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference12. Gabriela Barreto Lemos at the Austrian Academy of Sciences introduces and experimentally demonstrates a quantum imaging concept based on induced coherence without induced emission34. The experiment uses two separate down-conversion nonlinear crystals (numbered NL1 and NL2), each illuminated by the same pump laser, creating one pair of photons (denoted idler and signal). If the photon pair is created in NL1, one photon (the idler) passes through the object to be imaged and is overlapped with the idler amplitude created in NL2, its source thus being undefined.

Interference of the signal amplitudes coming from the two crystals then reveals the image of the object. The photons that pass through the imaged object (idler photons from NL1) are never detected, while we obtain images exclusively with the signal photons (from NL1 and NL2), which do not interact with the object.

The experiment is fundamentally different from previous quantum imaging techniques, such as interaction-free imaging5 or ghost imaging6789, because now the photons used to illuminate the object do not have to be detected at all and no coincidence detection is necessary. This enables the probe wavelength to be chosen in a range for which suitable detectors are not available. To illustrate this, the researchers show images of objects that are either opaque or invisible to the detected photons. This experiment is a prototype in quantum information—knowledge can be extracted by, and about, a photon that is never detected.

Donald Schwartz's curator insight, August 30, 2014 2:34 PM


As I live and breath, are there no mysteries any more?



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Do we live in a 2D hologram? New Fermilab experiment will test the nature of the universe

Do we live in a 2D hologram? New Fermilab experiment will test the nature of the universe | Amazing Science |
A unique experiment at the U.S. Department of Energy's Fermi National Accelerator Laboratory called the Holometer has started collecting data that will answer some mind-bending questions about our universe – including whether we live in a hologram.

Much like characters on a television show would not know that their seemingly 3D world exists only on a 2D screen, we could be clueless that our 3D space is just an illusion. The information about everything in our universe could actually be encoded in tiny packets in two dimensions. Get close enough to your TV screen and you'll see pixels, small points of data that make a seamless image if you stand back. Scientists think that the universe's information may be contained in the same way, and that the natural "pixel size" of space is roughly 10 trillion trillion times smaller than an atom, a distance that physicists refer to as the Planck scale.

"We want to find out whether space-time is a quantum system just like matter is," said Craig Hogan, director of Fermilab's Center for Particle Astrophysics and the developer of the holographic noise theory. "If we see something, it will completely change ideas about space we've used for thousands of years."

Quantum theory suggests that it is impossible to know both the exact location and the exact speed of subatomic particles. If space comes in 2D bits with limited information about the precise location of objects, then space itself would fall under the same theory of uncertainty . The same way that matter continues to jiggle (as quantum waves) even when cooled to absolute zero, this digitized space should have built-in vibrations even in its lowest energy state.

Essentially, the experiment probes the limits of the universe's ability to store information. If there are a set number of bits that tell you where something is, it eventually becomes impossible to find more specific information about the location – even in principle. The instrument testing these limits is Fermilab's Holometer, or holographic interferometer, the most sensitive device ever created to measure the quantum jitter of space itself.

Now operating at full power, the Holometer uses a pair of interferometers placed close to one another. Each one sends a one-kilowatt laser beam (the equivalent of 200,000 laser pointers) at a beam splitter and down two perpendicular 40-meter arms. The light is then reflected back to the beam splitter where the two beams recombine, creating fluctuations in brightness if there is motion. Researchers analyze these fluctuations in the returning light to see if the beam splitter is moving in a certain way – being carried along on a jitter of space itself.

"Holographic noise" is expected to be present at all frequencies, but the scientists' challenge is not to be fooled by other sources of vibrations. The Holometer is testing a frequency so high – millions of cycles per second – that motions of normal matter are not likely to cause problems. Rather, the dominant background noise is more often due to radio waves emitted by nearby electronics. The Holometer experiment is designed to identify and eliminate noise from such conventional sources.

"If we find a noise we can't get rid of, we might be detecting something fundamental about nature–a noise that is intrinsic to spacetime," said Fermilab physicist Aaron Chou, lead scientist and project manager for the Holometer. "It's an exciting moment for physics. A positive result will open a whole new avenue of questioning about how space works."

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Fascinating rhythm: Light pulses illuminate a rare black hole

Fascinating rhythm: Light pulses illuminate a rare black hole | Amazing Science |

The universe has so many black holes that it's impossible to count them all. There may be 100 million of these intriguing astral objects in our galaxy alone. Nearly all black holes fall into one of two classes: big, and colossal. Astronomers know that black holes ranging from about 10 times to 100 times the mass of our sun are the remnants of dying stars, and that supermassive black holes, more than a million times the mass of the sun, inhabit the centers of most galaxies.

But scattered across the universe like oases in a desert are a few apparent black holes of a more mysterious type. Ranging from a hundred times to a few hundred thousand times the sun's mass, these intermediate-mass black holes are so hard to measure that even their existence is sometimes disputed. Little is known about how they form. And some astronomers question whether they behave like other black holes.

Now a team of astronomers has accurately measured—and thus confirmed the existence of—a black hole about 400 times the mass of our sun in a galaxy 12 million light years from Earth. The finding, by University of Maryland astronomy graduate student Dheeraj Pasham and two colleagues, was published online August 17 in the journal Nature.

Pasham focused on one object in Messier 82, a galaxy in the constellation Ursa Major. Messier 82 is our closest "starburst galaxy," where young stars are forming. Beginning in 1999 a NASA satellite telescope, the Chandra X-ray Observatory, detected X-rays in Messier 82 from a bright object prosaically dubbed M82 X-1. Astronomers, including Mushotzky and co-author Tod Strohmayer of NASA's Goddard Space Flight Center, suspected for about a decade that the object was an intermediate-mass black hole, but estimates of its mass were not definitive enough to confirm that.

Between 2004 and 2010 NASA's Rossi X-Ray Timing Explorer (RXTE) satellite telescope observed M82 X-1 about 800 times, recording individual x-ray particles emitted by the object. Pasham mapped the intensity and wavelength of x-rays in each sequence, then stitched the sequences together and analyzed the result


Among the material circling the suspected black hole, he spotted two repeating flares of light. The flares showed a rhythmic pattern of light pulses, one occurring 5.1 times per second and the other 3.3 times per second – or a ratio of 3:2.

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New microhairs bend in magnetic field, directing water against gravity

New microhairs bend in magnetic field, directing water against gravity | Amazing Science |

MIT engineers have fabricated a new elastic material coated with microscopic, hairlike structures that tilt in response to a magnetic field.

Depending on the field’s orientation, the microhairs can tilt to form a path through which fluid can flow; the material can even direct water upward, against gravity.

Potential uses include waterproofing, anti-glare "smart windows” for buildings and cars, and rain-resistant clothing.

In experiments, the magnetically activated material directed not just the flow of fluid, but also light — much as window blinds tilt to filter the sun. Researchers say the work could lead to waterproofing and anti-glare applications, such as “smart windows” for buildings and cars.

“You could coat this on your car windshield to manipulate rain or sunlight,” says Yangying Zhu, a graduate student in MIT’s Department of Mechanical Engineering. “So you could filter how much solar radiation you want coming in, and also shed raindrops. This is an opportunity for the future.”

In the near term, the material could also be embedded in lab-on-a-chip devices to magnetically direct the flow of cells and other biological material through a diagnostic chip’s microchannels.

Zhu reports the details of the material this month in the journal Advanced Materials.

The inspiration for the microhair array comes partly from nature, Zhu says. For example, human nasal passages are lined with cilia — small hairs that sway back and forth to remove dust and other foreign particles. Zhu sought to engineer a dynamic, responsive material that mimics the motion of cilia.

In principle, more complex magnetic fields could be designed to create intricate tilting patterns throughout an array, say the researchers. Such patterns may be useful in directing cells through a microchip’s channels, or wicking moisture from a windshield. Since the material is flexible, it may even be woven into fabric to create rain-resistant clothing.


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Mapping the optimal route between two quantum states

Mapping the optimal route between two quantum states | Amazing Science |
As a quantum state collapses from a quantum superposition to a classical state or a different superposition, it will follow a path known as a quantum trajectory.

In a recent paper in Nature, scientists from the University of Rochester, University of California at Berkeley and Washington University in St. Louis have shown that it is possible to track these quantum trajectories and compare them to a recently developed theory for predicting the most likely path a system will take between two states.

Andrew N. Jordan, professor of physics at the University of Rochester and one of the authors of the paper, and his group had developed this new theory in an earlier paper. The results published this week show good agreement between theory and experiment.

For their experiment, the Berkeley and Washington University teams devised a superconducting qubit with exceptional coherence properties, permitting it to remain in a quantum superposition during the continuous monitoring. The experiment actually exploited the fact that any measurement will perturb a quantum system. This means that the optimal path will come about as a result of the continuous measurement and how the system is being driven from one quantum state to another.

Kater Murch, co-author and assistant professor at Washington University in St. Louis, explained that a key part of the experiment was being able to measure each of these trajectories while the system was changing, something that had not been possible until now.

Jordan compares the experiment to watching butterflies make their way one by one from a cage to nearby trees. "Each butterfly's path is like a single run of the experiment," said Jordan. "They are all starting from the same cage, the initial state, and ending in one of the trees, each being a different end state." By watching the quantum equivalent of a million butterflies make the journey from cage to tree, the researchers were in effect able to predict the most likely path a butterfly took by observing which tree it landed on (known as post-selection in quantum physics measurements), despite the presence of a wind, or any disturbance that affects how it flies, which is similar to the effect measuring has on the system.

"The experiment demonstrates that for any choice of final quantum state, the most likely or 'optimal path' connecting them in a given time can be found and predicted," said Jordan. "This verifies the theory and opens the way for active quantum control techniques." He explained that only if you know the most likely path is it possible to set up the system to be in the desired state at a specific time.

Via Jocelyn Stoller
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Relativity behind mercury's liquidity

Relativity behind mercury's liquidity | Amazing Science |

Why is mercury a liquid at room temperature? If you ask that question in a school classroom you will probably be told that relativity affects the orbitals of heavy metals, contracting them and changing how they bond. However, the first evidence that this explanation is correct has only just been published.

In the 1960s, Pekka Pyykkö, now at University of Helsinki, Finland, discovered that gold’s colour was the result of relativistic effects. He showed that the lower energy levels of the 6s orbital of gold means that the energy required to excite an electron from the 5d band lies in the visible rather than UV range of light. This means that gold absorbs blue light, while reflecting yellow and red light, and it is this that gives the metal its characteristic hue. If the energies of the two bands were calculated without including relativistic effects, the energy required is much greater. Further calculations have subsequently shown the influence of relativity on the colour and bond lengths of heavy metal compounds, as well as its importance in catalysis. However, the low melting point of mercury could still only be described as ‘probably’ due to relativistic effects.

An international team led by Peter Schwerdtfeger of Massey University Auckland in New Zealand used quantum mechanics to make calculations of the heat capacity of the metal either including or excluding relativistic effects. They showed that if they ignored relativity when making their calculations, the predicted melting point of mercury was 82°C. But if they included relativistic effects their answer closely matched the experimental value of -39°C.

Relativity states that objects get heavier the faster they move. In atoms, the velocity of the innermost electrons is related to the nuclear charge. The larger the nucleus gets the greater the electrostatic attraction and the faster the electrons have to move to avoid falling into it. So, as you go down the periodic table these 1s electrons get faster and faster, and therefore heavier, causing the radius of the atom to shrink. This stabilises some orbitals, which also have a relativistic nature of their own, while destabilising others. This interplay means that for heavy elements like mercury and gold, the outer electrons are stabilised. In mercury’s case, instead of forming bonds between neighbouring mercury atoms, the electrons stay associated with their own nuclei, and weaker interatomic forces such as van der Waals bonds hold the atoms together.

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Ultra-precise atomic clock will reveal if physical constants really are constant

Ultra-precise atomic clock will reveal if physical constants really are constant | Amazing Science |

A second is always a second. Nevertheless, no clocks are so precise that they can measure the exact duration of a second. So even the most precise atomic clocks are 0.000000000000000001 seconds off each second. Over the course of a few billion years that equals one second.

A single second off over the course of a few billion years may sound like a very precise clock -- and in a way it is but scientists from the University of Copenhagen would like a clock that is even more precise.

So now the scientists are suggesting that the atomic clocks around the world be connected by light rays; creating one big network of atomic clocks.

This network would measure time more precisely than ever before.

“A more precise clock would lead to a number of new, interesting possibilities,” says Professor Anders Søndberg Sørensen of the Niels Bohr Institute who recently co-authored a proposal for an improved atomic clock that was published in Nature Physics.

With more precise clocks come more precise experiments, and with more precise experiments come new technological possibilities. The Global Position System (GPS) for instance, only became possible when a new clock was invented that was so precise that it could measure how long it took for a signal from a GPS transmitter on Earth to reach satellites in space. Similarly, researchers hope that a more precise clock will lead to new scientific possibilities – and solve the debate over whether constants of nature are really constant at all.

Via Mariaschnee
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Ultrasound waves can spin a 200 nm wide gold nanomotor rod up to an impressive rotation of 150,000 rpm

Ultrasound waves can spin a 200 nm wide gold nanomotor rod up to an impressive rotation of 150,000 rpm | Amazing Science |

Scientists at the National Institute of Standards and Technology (NIST) have discovered that a gold nanorod submerged in water and exposed to high-frequency ultrasound waves can spin at an incredible speed of 150,000 RPM, about ten times faster than the previous record. The advance could lead to powerful nanomotors with important applications in medicine, high-speed machining, and the mixing of materials.

Take a rod only a few nanometers in size and find a way to make it spin as fast as possible, for as long as possible, and controlling it as precisely as possible. What you get is a nanomotor, a device that could one day be used to power hordes of tiny robots to build complex nanostructured materials or deliver drugs directly from inside a living cell.

Nanomotors have made giant strides in recent years: they've gotten much smaller and more reliable, and we can now also power them in many different ways. Available options include electricity, magnetic fields, blasting them with photons and, more recently, using ultrasound to rotate rods while they're submerged in water, which could prove very useful in a biological environment.

Previous studies have shown that applying a combination of ultrasound and magnetic fields can control both the spin and the forward motion of the nanorods, but nobody could tell just how fast they were spinning. Now, researchers at NIST have found that, despite being submerged in water, the rods are spinning at an impressive 150,000 RMP, which is 10 times faster than any nanoscale object submerged in liquid ever reported.

To clock the motor's speed, the researchers used gold rods which were 2 micrometers long and 300 nanometer wide. The rods were submerged in water and mixed with polystyrene nanoparticles, and positioned just above a speaker-type shaker.

The researchers will now focus on understanding exactly why the motors rotate (which is not yet well understood) and how the vortexes around the rods affects their interactions with each other.

A paper published in the journal ACS Nano describes the advance.

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Proton Spin Mystery Gains a New Clue

Proton Spin Mystery Gains a New Clue | Amazing Science |

Physicists long assumed a proton’s spin came from its three constituent quarks. New measurements suggest particles called gluons make a significant contribution.

Protons have a constant spin that is an intrinsic particle property like mass or charge. Yet where this spin comes from is such a mystery it’s dubbed the “proton spin crisis.” Initially physicists thought a proton’s spin was the sum of the spins of its three constituent quarks. But a 1987 experiment showed that quarks can account for only a small portion of a proton’s spin, raising the question of where the rest arises. The quarks inside a proton are held together by gluons, so scientists suggested perhaps they contribute spin. That idea now has support from a pair of studies analyzing the results of proton collisions inside the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, N.Y.
Physicists often explain spin as a particle’s rotation, but that description is more metaphorical than literal. In fact, spin is a quantum quantity that cannot be described in classical terms. Just as a proton is not really a tiny marble but rather a jumble of phantom particles appearing and disappearing continuously, its spin is a complex probabilistic property. Yet it is always equal to one half.
Quarks also have a spin of one half. Physicists originally assumed that two of the proton’s three quarks were always spinning in opposite directions, canceling one another out, leaving the remaining one half as the proton’s total spin. “That was the naïve idea 25 years ago,” says Daniel de Florian of the University of Buenos Aires, leader of one of the new papers, which was published July 2, 2014 in Physical Review Letters. “By the end of the ‘80s it was possible to measure the contribution of the spin of the quarks to the spin of the proton, and the first measurement showed it was 0 percent. That was a very big surprise.” Later measurements actually suggested quarks can contribute up to 25 percent of the proton’s total spin, but that still leaves the lion’s share unaccounted for.
Gluons are also present inside protons as the representatives of the strong nuclear force, a fundamental interaction that binds the quarks together. Gluons each have a spin of 1, and depending on which direction it is they could add up to make most of rest of the proton’s spin. Measuring their contribution is a tricky task. RHIC is the only experiment that can address the question, because it is the only particle accelerator built to collide “spin-polarized” protons, meaning that the particles are all spinning in a certain direction when they crash. (At the more powerful Large Hadron Collider in Switzerland, the particles’ spins are not aligned.)
When two protons slam together, their interaction is controlled by the strong force, so gluons are intimately involved. If gluon spin is an important ingredient of proton spin, then the orientation of the colliding protons’ spins should affect the outcome. Scientists would expect collisions between two protons whose spins were aligned would happen at a different frequency than collisions between those spinning in opposite directions. And according to recent data from RHIC, there is a difference. “If there is no preferred position, the difference will be exactly zero,” says University of Oxford physicist Juan Rojo, a member of the so-called NNPDF Collaboration that wrote the second paper, which was submitted to Nuclear Physics B.

“Since the asymmetry is not zero, this tells us the distribution of the spin is not trivial.” Rojo’s team calculated that gluons probably contribute about half the spin that quarks do to the proton. De Florian and his colleagues analyzed the same data from RHIC, but used a different mathematical analysis to calculate the gluon contribution. They also found that gluon spin must be significantly involved. “This data for the first time shows the gluon polarization is actually nonzero; we see the gluons are polarized,” de Florian says. “Basically they could be responsible for the rest of the proton spin, but the uncertainty is very large.”

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'Solid' light could compute previously unsolvable problems

'Solid' light could compute previously unsolvable problems | Amazing Science |
Researchers at Princeton University have begun crystallizing light as part of an effort to answer fundamental questions about the physics of matter.

The researchers are not shining light through crystal – they are transforming light into crystal. As part of an effort to develop exotic materials such as room-temperature superconductors, the researchers have locked together photons, the basic element of light, so that they become fixed in place.

"It's something that we have never seen before," said Andrew Houck, an associate professor of electrical engineering and one of the researchers. "This is a new behavior for light."

The results raise intriguing possibilities for a variety of future materials. But the researchers also intend to use the method to address questions about the fundamental study of matter, a field called condensed matter physics.

"We are interested in exploring – and ultimately controlling and directing – the flow of energy at the atomic level," said Hakan Türeci, an assistant professor of electrical engineering and a member of the research team. "The goal is to better understand current materials and processes and to evaluate materials that we cannot yet create."

The team's findings, reported online on Sept. 8 in the journal Physical Review X, are part of an effort to answer fundamental questions about atomic behavior by creating a device that can simulate the behavior of subatomic particles. Such a tool could be an invaluable method for answering questions about atoms and molecules that are not answerable even with today's most advanced computers.

In part, that is because current computers operate under the rules of classical mechanics, which is a system that describes the everyday world containing things like bowling balls and planets. But the world of atoms and photons obeys the rules of quantum mechanics, which include a number of strange and very counterintuitive features. One of these odd properties is called "entanglement" in which multiple particles become linked and can affect each other over long distances.

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New study revisits Miller-Urey experiment at the quantum level with the aid of computers

New study revisits Miller-Urey experiment at the quantum level with the aid of computers | Amazing Science |
For the first time, researchers have reproduced the results of the Miller-Urey experiment in a computer simulation, yielding new insight into the effect of electricity on the formation of life's building blocks at the quantum level.

In 1953, American chemist Stanley Miller had famously electrified a mixture of simple gas and water to simulate lightning and the atmosphere of early Earth. The revolutionary experiment—which yielded a brownish soup of amino acids—offered a simple potential scenario for the origin of life's building blocks. Miller's work gave birth to modern research on pre-biotic chemistry and the origins of life.

For the past 60 years, scientists have investigated other possible energy sources for the formation of life's building blocks, including ultra violet light, meteorite impacts, and deep sea hydrothermal vents.

In this new study, Antonino Marco Saitta, of the Université Pierre et Marie Curie, Sorbonne, in Paris, France and his colleagues wanted to revisit Miller's result with electric fields, but from a quantum perspective.

Saitta and study co-author Franz Saija, two theoretical physicists, had recently applied a new quantum model to study the effects of electric fields on water, which had never been done before. After coming across a documentary on Miller's work, they wondered whether the quantum approach might work for the famous spark-discharge experiment.

The method would also allow them to follow individual atoms and molecules through space and time—and perhaps yield new insight into the role of electricity in Miller's work.

"The spirit of our work was to show that the electric field is part of it," Saitta said, "without necessarily involving lightning or a spark."  Another key insight from their study is that the formation of some of life's building blocks may have occurred on mineral surfaces, since most have strong natural electric fields.

"The electric field of mineral surfaces can be easily 10 or 20 times stronger than the one in our study," Saitta said. "The problem is that it only acts on a very short range. So to feel the effects, molecules would have to be very close to the surface." "I think that this work is of great significance," said François Guyot, a geochemist at the French Museum of Natural History.

"Regarding the mineral surfaces, strong electric fields undoubtedly exist at their immediate proximity. And because of their strong role on the reactivity of organic molecules, they might enhance the formation of more complex molecules by a mechanism distinct from the geometrical concentration of reactive species, a mechanisms often proposed when mineral surfaces are invoked for explaining the formation of the first biomolecules."

One of the leading hypotheses in the field of life's origin suggests that important prebiotic reactions may have occurred on mineral surfaces. But so far scientists don't fully understand the mechanism behind it.

"Nobody has really looked at electric fields on mineral surfaces," Saitta said. "My feeling is that there's probably something to explore there."

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System that prompts objects to ‘float’ in suspension could prove boon to manufacturing with fragile materials

System that prompts objects to ‘float’ in suspension could prove boon to manufacturing with fragile materials | Amazing Science |
Harvard scientists have developed a system for using magnetic levitation technology to manipulate nonmagnetic materials, potentially enabling manufacturing with materials that are too fragile for traditional methods.

While assembly lines have been the gold standard in manufacturing for more than a century, and have put together everything from Model T’s to tablet computers, one aspect of their operation has remained constant: the need for a hand, robotic or human, to manipulate objects.

If Anand Bala Subramaniam, a postdoctoral fellow in chemistry and chemical biology, has his way, however, that could soon change.

Working in the lab of Woodford L. and Ann A. Flowers University Professor George Whitesides, Subramaniam and colleagues, including Dian Yang, Hai-Dong Yu, Alex Nemiroski, Simon Tricard, Audrey K. Ellerbee, and Siowling Soh, have developed a system for using magnetic levitation, or maglev, technology to manipulate nonmagnetic materials, potentially enabling the use of materials that are too fragile for traditional manufacturing methods. The system is described in an Aug. 25 paper published in the Proceedings of the National Academy of Sciences.

“What we’ve demonstrated in this paper is a noncontact method for manipulating objects,” Subramaniam said. “A conventional method for manufacturing is to start with simple components that are easy to manufacture, which are then assembled into more complex objects. Typically, robotic arms grasp the components and twist or turn them during the assembly process. That works very well for hard objects. But soft and sticky materials, which are of interest for building bio-mimetic objects, could easily be damaged.”

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Fusion Lasers Compress Diamond To Pressures Of 50 Million Earth Atmospheres (5 Terapascals)

Fusion Lasers Compress Diamond To Pressures Of 50 Million Earth Atmospheres (5 Terapascals) | Amazing Science |

Physicists reported recently that they have successfully used the lasers built for fusion reactions at the National Ignition Facilityin Lawrence Livermore National Laboratory to compress a synthetic diamond to pressures of 50 million Earth atmospheres (5 terapascals).  For the first time scientists measured pressure-density curves of matter at trillion pascal pressures, an extreme environment found in the core of gas giants and super Earth planets.

A tiny sample of synthetic diamond, millimeter-sized and in the shape of a cylinder, was held upright and put into the crosshairs of 176 high powered fusion laser beams.  The beams have total peak power of 2200 gigawatts (GW).  In comparison, a nuclear power plant only produces as much as energy at a rate of 0.5 to 2 GW.  Since power is the energy output over time, the laser beams can only run a very short time at such power, so the total output of energy is not high.

Half the beams are focused on the top half of the cylinder and the other half on the bottom.  This squeezes the cylinder when the lasers fire.  Upon firing, the physicists measured the rate of diamond material moving under the tremendous heating and counter-reactions.  As the cylindrical piece of diamond is compressed, its middle bulges out at extremely high velocities.  The measured peak velocity was 109,000 miles per hour, or about 45 kilometers per second.

They found that at the peak pressure of 5 trillion pascals, or equivalently 50 million Earth atmospheres, the density of the diamond had more than tripled.  Therefore the diamond was compressed to three times a smaller volume than before, making its density equal to that of lead.

The results were compared to a type of computer simulation called density functional theory (DFT).  DFT is based on a branch of physics known as quantum mechanics.  While it is an approximate method, meaning that accuracy of representing the underlying physics is sacrificed for purposes of speed, it is quite successful in predicting many complex aspects of matter.  The researchers used two types of theories in DFT and showed that the measured results fall right in between the computer predictions.

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How the Computer of the Future Keeps Itself Cool

How the Computer of the Future Keeps Itself Cool | Amazing Science |
A team of theoretical physicists at the University of Hamburg, Germany have just published the schematics for a method that tackles the biggest hurdle in quantum computing: keeping everything cool.

One of the biggest issues facing the development of quantum computers—tomorrow's supercomputers based on the strange principles of quantum physics—is keeping everything cool. Electronics make heat, and while your laptop and smartphone can use fans or heat-absorbing water tanks, those just won't cut it for quantum computing, which will take advantage of the quirks of quantum mechanics to create computers that calculate at insane speeds. 

"When you start to make electronics smaller and denser, not only are you making much more heat in the same amount of volume, but it's much harder for the heat to flow outward," says Peter Nalbach, a theoretical physicist at the University of Hamburg, Germany. 

At this stage, our early attempts at quantum computers have to be kept at a temperature barely hovering above the insanely cold, dead-standstill of absolute zero. If you're trying to develop a large-scale quantum computer, Nalbach, says, "at a certain point, you'll have to actively transport heat out of the spot where it's created," Until now, engineers had no idea exactly how to do this. 

But Nalbach and his colleagues have just published the schematics of a method to individually target and cool the physical building blocks of tomorrow's quantum computers. In their outline, recently published in the physics journal Physical Review Letters, the physicists show how they can halve the temperature of individual quantum dots—nano-sized pieces of crystal that are currently being investigated as qubits for quantum computers

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WIRED: Radical New Theory Could Kill the Multiverse Hypothesis and Gets Rid of Concepts Like "Length" and "Mass"

WIRED: Radical New Theory Could Kill the Multiverse Hypothesis and Gets Rid of Concepts Like "Length" and "Mass" | Amazing Science |
Mass and length may not be fundamental properties of nature, according to new ideas bubbling out of the multiverse.

Though galaxies look larger than atoms and elephants appear to outweigh ants, some physicists have begun to suspect that size differences are illusory. Perhaps the fundamental description of the universe does not include the concepts of “mass” and “length,” implying that at its core, nature lacks a sense of scale.

This little-explored idea, known as scale symmetry, constitutes a radical departure from long-standing assumptions about how elementary particles acquire their properties. But it has recently emerged as a common theme of numerous talks and papers by respected particle physicists. With their field stuck at a nasty impasse, the researchers have returned to the master equations that describe the known particles and their interactions, and are asking: What happens when you erase the terms in the equations having to do with mass and length?

Nature, at the deepest level, may not differentiate between scales. With scale symmetry, physicists start with a basic equation that sets forth a massless collection of particles, each a unique confluence of characteristics such as whether it is matter or antimatter and has positive or negative electric charge. As these particles attract and repel one another and the effects of their interactions cascade like dominoes through the calculations, scale symmetry “breaks,” and masses and lengths spontaneously arise.

Similar dynamical effects generate 99 percent of the mass in the visible universe. Protons and neutrons are amalgams — each one a trio of lightweight elementary particles called quarks. The energy used to hold these quarks together gives them a combined mass that is around 100 times more than the sum of the parts. “Most of the mass that we see is generated in this way, so we are interested in seeing if it’s possible to generate all mass in this way,” said Alberto Salvio, a particle physicist at the Autonomous University of Madrid and the co-author of a recent paper on a scale-symmetric theory of nature.

In the equations of the “Standard Model” of particle physics, only a particle discovered in 2012, called the Higgs boson, comes equipped with mass from the get-go. According to a theory developed 50 years ago by the British physicist Peter Higgs and associates, it doles out mass to other elementary particles through its interactions with them. Electrons, W and Z bosons, individual quarks and so on: All their masses are believed to derive from the Higgs boson — and, in a feedback effect, they simultaneously dial the Higgs mass up or down, too.

The new scale symmetry approach rewrites the beginning of that story. “The idea is that maybe even the Higgs mass is not really there,” said Alessandro Strumia, a particle physicist at the University of Pisa in Italy. “It can be understood with some dynamics.”

The concept seems far-fetched, but it is garnering interest at a time of widespread soul-searching in the field. When the Large Hadron Collider at CERN Laboratory in Geneva closed down for upgrades in early 2013, its collisions had failed to yield any of dozens of particles that many theorists had included in their equations for more than 30 years. The grand flop suggests that researchers may have taken a wrong turn decades ago in their understanding of how to calculate the masses of particles.

“We’re not in a position where we can afford to be particularly arrogant about our understanding of what the laws of nature must look like,” said Michael Dine, a professor of physics at the University of California, Santa Cruz, who has been following the new work on scale symmetry. “Things that I might have been skeptical about before, I’m willing to entertain.”

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Electron spin changes as a general mechanism for general anesthesia?

Electron spin changes as a general mechanism for general anesthesia? | Amazing Science |

How does consciousness work? Few questions if any could be more profound. Lipid solubility appears to be one key clue to anesthesia. The empirical cornerstone of anesthesiology is a 100 year old rule of thumb known as the Meyer-Overton relationship. It provides that the potency of general anesthetics (GAs), regardless of their size or structure, is approximately proportional to how soluble they are in lipids. Since that time, studies have suggested that GAs can also bind to lipid-like parts of proteins, presumably those near or embedded within cell membranes.

The first real stab at explaining the "how" of anesthetics, as opposed to just the "where", has now been taken by Turin and his colleagues Efthimios Skoulakis and Andrew Horsfield. Their new work, just published in PNAS, suggests that volatile anesthetics operate by perturbing the internal electronic structure of proteins. This would lead to changes in electron currents in those proteins, in cells, and in the organism. They don't just theorize about these effects, they actually measure the electron currents in anesthetized flies using a technique known as electron spin resonance (often called electron paramagnetic resonance).

ESR is similar to nuclear magnetic resonance, the techno-phenomenon at heart of the modern MRI machine. The main difference is that in ESR excited electron spins are measured instead of proton resonance. Typically, microwaves are applied in the presence of a magnetic field to a sample (or whole organism) inside the resonator cavity of an ESR spectrometer.What Turin and colleagues have shown is that the total amount of free electron spins in fruit flies increases when they are exposed to general anesthetics. The amount of free spins generated during anesthesia is independent of melanin content and far larger than any signal previously measured from free radicals which are the other source of spin.

To account for the fact that a very broad class of compounds act as volatile anesthetics the researchers propose a unitary mechanism for their action involving electrons. They note that the smallest among them, Xenon (Xe), presents a puzzle to chemical theories of anesthetic action. Xe is a wonderful (if expensive) anesthetic but it has no biologically relevant chemistry to speak of— it is completely inert. Furthermore, it persists as a perfect sphere of electron density and so is devoid of any possibly interesting shape. However, as Turin and colleagues point out, "Xe has physics". In particular, it can conduct electrons, as the IBM researchers who first used a scanning tunneling microscope to write the company's logo in Xe atoms found out.

To see whether this property would apply to all anesthetics, and not just Xe, Turin used a modeling technique called density functional theory to show that Xe and other anesthetics effect the highest occupied molecular orbit (HOMO) of the alpha helices common to membrane proteins. The HOMO level for organic molecules or semiconductors is analogous to what the valence band maximum is to inorganic semiconductors. Intriguingly, while all the anesthetics were found to extend the alpha helix HOMO level, similar molecules with strong convulsant effects on the brain, but no anesthetic effects, had the smallest HOMO effect.

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The Strangeness of Quantum Mechanics and the Delayed Choice Quantum Eraser

The Strangeness of Quantum Mechanics and the Delayed Choice Quantum Eraser | Amazing Science |

Feynman once said that all the surprising wisdom of quantum mechanics is hiding in the double slit experiment. If you think about it carefully enough, you will ultimately figure out all the important and amazing new features of the world that quantum mechanics uncovers.

However, many people disagree and they tend to expect that every time they add a new prism or a new laser or a beam splitter to an experiment, the situation becomes more confusing than ever before and there is a new "hope" that a disagreement with quantum mechanics will be found.

More complex experiments only make the situation more contrived - but the basic scheme of how quantum mechanics works is unchanged. Also, all the errors that lead most people to believe that there is something paradoxical about quantum mechanics keep on repeating themselves.

The list of important experiments:

  1. The ordinary double-slit experiment
  2. Wheeler's delayed choice experiment
  3. An EPR experiment with a single pair of particles
  4. Delayed choice quantum eraser
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New correction to speed of light could explain SN1987 dual-pulse neutrino burst

New correction to speed of light could explain SN1987 dual-pulse neutrino burst | Amazing Science |

The effect of gravity on virtual electron–positron pairs as they propagate through space could lead to a violation of Einstein's equivalence principle, according to calculations by James Franson at the University of Maryland, Baltimore County. While the effect would be too tiny to be measured directly using current experimental techniques, it could explain a puzzling anomaly observed during the famous SN1987 supernova of 1987.

In modern theoretical physics, three of the four fundamental forces – electromagnetism, the weak nuclear force and the strong nuclear force – are described by quantum mechanics. The fourth force, gravity, does not currently have a quantum formulation and is best described by Einstein's general theory of relativity. Reconciling relativity with quantum mechanics is therefore an important and active area of physics.

An open question for theoretical physicists is how gravity acts on a quantum object such as a photon. Astronomical observations have shown repeatedly that light is attracted by a gravitational field. Traditionally, this is described using general relativity: the gravitational field bends space–time, and the light is slowed down (and slightly deflected) as it passes through the curved region. In quantum electrodynamics, a photon propagating through space can occasionally annihilate with itself, creating a virtual electron–positron pair. Soon after, the electron and positron recombine to recreate the photon. If they are in a gravitational potential then, for the short time they exist as massive particles, they feel the effect of gravity. When they recombine, they will create a photon with an energy that is shifted slightly and that travels slightly slower than if there was no gravitational potential.

Franson scrutinized these two explanations for why light slows down as it passes through a gravitational potential. He decided to calculate how much the light should slow down according to each theory, anticipating that he would get the same answer. However, he was in for a surprise: the predicted changes in the speed of light do not match, and the discrepancy has some very strange consequences.

Franson calculated that, treating light as a quantum object, the change in a photon's velocity depends not on the strength of the gravitational field, but on the gravitational potential itself. However, this leads to a violation of Einstein's equivalence principle – that gravity and acceleration are indistinguishable – because, in a gravitational field, the gravitational potential is created along with mass, whereas in a frame of reference accelerating in free fall, it is not. Therefore, one could distinguish gravity from acceleration by whether a photon slows down or not when it undergoes particle–antiparticle creation.

An important example is a photon and a neutrino propagating in parallel through space. A neutrino cannot annihilate to create an electron–positron pair, so the photon will slow down more than the neutrino as they pass through a gravitational field, potentially letting the neutrino travel faster than light through that region of space. However, if the problem is viewed in a frame of reference falling freely into the gravitational field, neither the photon nor the neutrino slows down at all, so the photon continues to travel faster than the neutrino.

While the idea that the laws of physics can be dependent on one's frame of reference seems nonsensical, it could explain an anomaly in the 1987 observation of supernova SN1987a. An initial pulse of neutrinos was detected 7.7 hours before the first light from SN1987a reached Earth. This was followed by a second pulse of neutrinos, which arrived about three hours before the supernova light. Supernovae are expected to emit large numbers of neutrinos and the three-hour gap between the second burst of neutrinos and the arrival of the light agrees with the current theory of how a star collapses to create a supernova.

The first pulse of neutrinos is generally thought to be unrelated to the supernova. However, the probability of such a coincidence is statistically unlikely. If Franson's results are correct, then the 7.7-hour gap between the first pulse of neutrinos and the arrival of the light could be explained by the gravitational potential of the Milky Way slowing down the light. This does not explain why two neutrino pulses preceded the light, but Franson suggests the second pulse could be related to a two-step collapse of the star.

The research is published in the New Journal of Physics.

Infospectives's curator insight, August 2, 2014 1:51 PM

I love this..."NEW' correction to the speed of light.  Since when did we start messing about with it?

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Quantum Cheshire Cat: Scientists have for the first time separated a particle from one of its physical properties

Quantum Cheshire Cat: Scientists have for the first time separated a particle from one of its physical properties | Amazing Science |

The phenomenon is named after the curious feline in Alice in Wonderland, who vanishes leaving only its grin. Researchers took a beam of neutrons and separated them from their magnetic moment, like passengers and their baggage at airport security. They describe their feat in Nature Communications.

The same separation trick could in principle be performed with any property of any quantum object, say researchers from Vienna University of Technology. Their technique could have a useful application in metrology - helping to filter out disturbances during high-precision measurements of quantum systems.

The idea of a "quantum Cheshire Cat" was first proposed in 2010 by Dr Jeff Tollaksen from Chapman University, a co-author on this latest paper. In the world familiar to us, an object and its properties are always bound together. A rotating ball, for instance, cannot become separated from its spin.

The cat (the neutron) goes via the upper beam path, while its grin (the magnetic moment) goes via the lower. But quantum theory predicts that a particle (such as a photon or neutron) can become physically separated from one of its properties - such as its polarisation or its magnetic moment.

"We find the cat in one place, and its grin in another," as the researchers once put itThe feline analogy is a nod to Schrodinger's Cat - the infamous thought experiment in which a cat in a box is both alive and dead simultaneously - illustrating a quantum phenomenon known as superposition.

To prove that the Cheshire Cat is not just a cute theory, the researchers used an experimental set-up known as an interferometer, at the Institute Laue-Langevin (ILL) in Grenoble, France.

A neutron beam was passed through a silicon crystal, sending it down two different paths - like passengers and their luggage at airport security.

By applying filters and a technique known as "post-selection", they were able to detect the physical separation of the neutrons from their magnetic moment - as measured by the direction of their spin.

"The system behaves as if the neutrons go through one beam path, while their magnetic moment travels along the other," the researchers reported.

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How to maintain quantum entanglement in amplified signals?

How to maintain quantum entanglement in amplified signals? | Amazing Science |

Physicists Sergei Filippov (MIPT and Russian Quantum Center at Skolkovo) and Mario Ziman (Masaryk University in Brno, Czech Republic, and the Institute of Physics in Bratislava, Slovakia) have found a way to preserve quantum entanglement of particles passing through an amplifier and, conversely, when transmitting a signal over long distances. Details are provided in an article published in the journal Physical Review A.

The laws of quantum mechanics do not allow for the teleportation of objects and people, but it is already possible to quantum teleport single photons and atoms, which opens up exciting opportunities for the creation of new computing devices and communication lines. Due to specific quantum effects, a quantum computer will be able to efficiently solve certain problems, for example, hacking codes used in banking, but for now it is still just a theoretical possibility. In practice, quantum computing and teleportation are obstructed by a process called decoherence.

Decoherence is the destruction of the quantum state due to the interaction of a quantum system with the outside world. For experiments in quantum computing, scientists use single atoms caught in magnetic traps and cooled to temperatures close to absolute zero. After going through kilometers of fiber, photons cease to be quantum entangled in most cases and become ordinary, unrelated light quanta.

To create an effective quantum computing system, scientists have to solve a number of problems, including preserving quantum entanglement when the signal abates and when it passes through an amplifier. Fiber-optic cables on the ocean bed contain a great deal of special amplifiers composed of optical glass and rare earth elements. It is these amplifiers that make it possible to watch high-resolution videos stored on a server in California from the MIPT campus or a university in Beijing.

In their article, Filippov and Ziman say that a certain class of signals can be transmitted so that the risk ofruining quantum entanglement becomes much lower. In this case, neither the attenuation nor the amplification of a signal ruins the entanglement. To achieve this effect, it is necessary to have the particles in a special, non-Gaussian state, or, as physicists put it, "the wave function of the particles in the coordinate representation should not be in the form of a Gaussian wave packet." A wave function is a basic concept of quantum mechanics, and Gaussian distribution is a major mathematical function used not only by physicists but also by statisticians, sociologists and economists.

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China plans particle colliders that would completely dwarf CERN's Large Hadron Collider

China plans particle colliders that would completely dwarf CERN's Large Hadron Collider | Amazing Science |

The 27-kilometer Large Hadron Collider at CERN could soon be overtaken as the world’s largest particle smasher by a proposed Chinese machine. Proposals for two accelerators could see country become collider capital of the world.

For decades, Europe and the United States have led the way when it comes to high-energy particle colliders. But a proposal by China that is quietly gathering momentum has raised the possibility that the country could soon position itself at the forefront of particle physics.

Scientists at the Institute of High Energy Physics (IHEP) in Beijing, working with international collaborators, are planning to build a ‘Higgs factory’ by 2028 — a 52-kilometre underground ring that would smash together electrons and positrons. Collisions of these fundamental particles would allow the Higgs boson to be studied with greater precision than at the much smaller Large Hadron Collider (LHC) at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland.

Physicists say that the proposed US$3-billion machine is within technological grasp and is considered conservative in scope and cost. But China hopes that it would also be a stepping stone to a next-generation collider — a super proton–proton collider — in the same tunnel.

European and US teams have both shown interest in building their own super collider (see Nature 503, 177; 2013), but the huge amount of research needed before such a machine could be built means that the earliest date either can aim for is 2035. China would like to build its electron–positron collider in the meantime, unaided by international funding if needs be, and follow it up as fast as technologically possible with the super proton collider. Because only one super collider is likely to be built, China’s momentum puts it firmly in the driving seat.

Speaking this month at the International Conference on High Energy Physics in Valencia, Spain, IHEP director Yifang Wang said that, to secure government support, China wanted to work towards a more immediate goal than a super collider by 2035. “You can’t just talk about a project which is 20 years from now,” he said.

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