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Archive for the ‘quantum physics’ category: Page 786

Jul 13, 2016

Researchers Develop A Universal Quantum Gate

Posted by in categories: computing, particle physics, quantum physics

The universal quantum gate to enable long distance communications with QC without degradation.


Scientists have now developed a universal quantum gate, which could become the key component in a quantum computer.

Light particles completely ignore each other. In order that these particles can nevertheless switch each other when processing quantum information, researchers at the Max Planck Institute of Quantum Optics in Garching have now developed a universal quantum gate. Quantum gates are essential elements of a quantum computer. Switching them with photons, i.e. light particles, would have practical advantages over operating them with other carriers of quantum information.

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Jul 13, 2016

Air Force wants to leap ahead in quantum computing

Posted by in categories: computing, military, quantum physics

US AF does need to get onboard quickly or be left in the dust.


Quantum computing could be a competitive advantage for the U.S. military, and the Air Force Research Lab wants to keep pace.

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Jul 13, 2016

Diamond coupled to carbon nanotube could be used for quantum information processing

Posted by in categories: nanotechnology, quantum physics

Why synthetic diamonds are critical to the QC story.


(Phys.org)—By carefully placing a tiny piece of diamond within a few nanometers of a carbon nanotube, and then sending an electric current through the nanotube, researchers have designed a device that could one day form the building blocks of quantum information processing systems. In their recent study, they have shown that the electrified nanotube’s mechanical vibrations couple to the magnetic (or spin) properties of defects in the diamond. This coupling allows for the quantum states of the nanotube and diamond to be transferred to each other as well as to a second diamond positioned several micrometers away.

The researchers, Peng-Bo Li et al., have published a paper on the new hybrid quantum device in a recent issue of Physical Review Letters.

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Jul 13, 2016

The quantum origin of time

Posted by in categories: futurism, quantum physics

In our experience the past is the past and the future is the future, but sometimes the two can cross over.

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Jul 13, 2016

Physicists collide ultracold atoms to observe key quantum principle

Posted by in categories: particle physics, quantum physics

Physicists from New Zealand’s University of Otago have used steerable ‘optical tweezers’ to split minute clouds of ultracold atoms and slowly smash them together to directly observe a key theoretical principle of quantum mechanics.

The principle, known as Pauli Exclusion, places fundamental constraints on the behavior of groups of identical particles and underpins the structure and stability of atoms as well as the mechanical, electrical, magnetic and chemical properties of almost all materials.

Otago Physics researcher Associate Professor Niels Kjærgaard led the research, which is newly published in the prestigious journal Nature Communications (“Multiple scattering dynamics of fermions at an isolated p-wave resonance”).

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Jul 13, 2016

Collapse: Has quantum theory’s greatest mystery been solved?

Posted by in categories: particle physics, quantum physics

Our best theory of reality says things only become real when we look at them. Understanding how the universe came to be requires a better explanation.

By Jon Cartwright

WHERE, when you aren’t looking at it, is a subatomic particle? A quantum physicist would probably answer: sort of all over the place. An unobserved particle is a wisp of reality, a shimmer of existence – there isn’t a good metaphor for it, because it is vague both by definition and by nature. Until you do have a peek. Then it becomes a particle proper, it can be put into words, it is a thing with a place.

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Jul 12, 2016

Sharper than living matter permits

Posted by in categories: biological, quantum physics

Researchers at the Max Planck Institute of Molecular Physiology in Dortmund have now found a way to pinpoint the positions of individual molecules while at the same time measuring their activity and interactions in the same living cell. A dedicated cooling protocol on a microscope allows to pause cellular life at subzero temperatures, to let it continue to live again after warming. From the series of individual snapshots obtained, the researchers are able to form a precise spatial-temporal picture of the activity patterns of individual molecules within individual cells.

Fluorescence microscopy allows seeing where biological molecules are in cells. However, what Werner Heisenberg formulated for quantum physics to a certain extent has its analogy in biology: In the living state one can observe the collective movement of molecules in cells, which makes it however difficult to determine their exact positions. Paradoxically, the molecular dynamics that sustain life have to be halted to record the position of molecules using high-resolution fluorescence microscopy.

Living matter maintains its structure by energy consumption, which results in dynamic molecular patterns in cells that are difficult to observe by fluorescence microscopy, because the molecules are too numerous and their movements too fast. To tackle this problem a choice needs to be made: to precisely record the position of the molecules in a ‘dead’ state or to follow their collective behaviour in the living state. Although researchers have been able to stop movements in cells by chemical fixation, such methods lead to irreversible cell death and the acquired images of molecular patterns are not representative of a living system.

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Jul 12, 2016

Missouri S&T physicist works to predict atom movement

Posted by in categories: particle physics, quantum physics

By laser-cooling atom clusters and studying their movements, a Missouri University of Science and Technology researcher hopes to better understand how atoms and their components are impacted and directed by environmental factors.

With a $400,000 grant from the National Science Foundation, Dr. Daniel Fischer, assistant professor of physics at Missouri S&T, tests the limits of quantum mechanics through his project titled “Control and Analysis of Atomic Few-Body Dynamics.”

In a hand-built vacuum chamber, Fischer manipulates lithium atoms by trapping them in a magnetic field and then shooting them with different lasers. This gives Fischer a large variety of initial states to test. Tests range from single, polarized atoms to larger groups that are laser-cooled to a consistent energy level. By doing so, Fischer works to help unravel the “few-body problem” that continues to confound the world of physics.

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Jul 11, 2016

Micron sized onchip quantum dot lasers will enable faster communication and computing

Posted by in categories: computing, quantum physics

Micron sized onchip making printing and communication faster.


Researchers designed subwavelength micro-disk lasers (MDLs) as small as 1μm in diameter on exact (001) silicon, using colloidal lithography (dispersing silica colloidal beads as hard masks before etching the prepared QD material layers). Micron sized lasers are 1,000 times shorter in length, and 1 million times smaller than current onchip lasers.

A group of scientists from Hong Kong University of Science and Technology; the University of California, Santa Barbara; Sandia National Laboratories and Harvard University were able to fabricate tiny lasers directly on silicon — a huge breakthrough for the semiconductor industry and well beyond.

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Jul 11, 2016

Atomic bits despite zero-point energy? Jülich scientists explore novel ways of developing stable nanomagnets

Posted by in categories: computing, mobile phones, nanotechnology, particle physics, quantum physics

Stable nanomagnets that ultimately improves data storage on the smallest of devices.


Abstract: So-called “zero-point energy” is a term familiar to some cinema lovers or series fans; in the fictional world of animated films such as “The Incredibles” or the TV series “Stargate Atlantis”, it denotes a powerful and virtually inexhaustible energy source. Whether it could ever be used as such is arguable. Scientists at Jülich have now found out that it plays an important role in the stability of nanomagnets. These are of great technical interest for the magnetic storage of data, but so far have never been sufficiently stable. Researchers are now pointing the way to making it possible to produce nanomagnets with low zero-point energy and thus a higher degree of stability (Nano Letters, DOI: 10.1021/acs.nanolett.6b01344).

Since the 1970s, the number of components in computer chips has doubled every one to two years, their size diminishing. This development has made the production of small, powerful computers such as smart phones possible for the first time. In the meantime, many components are only about as big as a virus and the miniaturization process has slowed down. This is because below approximately a nanometre, a billionth of a meter in size, quantum effects come into play. They make it harder, for example, to stabilise magnetic moments. Researchers worldwide are looking for suitable materials for magnetically stable nanomagnets so that data can be stored safely in the smallest of spaces.

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