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Archive for the ‘quantum physics’ category: Page 746

Nov 10, 2016

Two paths at once: Watching the buildup of quantum superpositions

Posted by in categories: particle physics, quantum physics

Scientists have observed how quantum superpositions build up in a helium atom within femtoseconds. Just like in the famous double-slit experiment, there are two ways to reach the final outcome.

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Nov 10, 2016

Stable quantum bits can be made from complex molecules

Posted by in categories: chemistry, computing, information science, quantum physics

Quantum computing is about to get more complex. Researchers have evidence that large molecules made of nickel and chromium can store and process information in the same way bytes do for digital computers. The researchers present algorithms proving it’s possible to use supramolecular chemistry to connect “qubits,” the basic units for quantum information processing, in Chem on November 10. This approach would generate several kinds of stable qubits that could be connected together into structures called “two-qubit gates.”

“We have shown that the chemistry is achievable for bringing together two-qubit gates,” says senior author Richard Winpenny, Head of the University of Manchester School of Chemistry. “The molecules can be made and the two-qubit gates assembled. The next step is to show that these two-qubit gates work.”

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Nov 9, 2016

Australians researchers have built a better qubit

Posted by in categories: computing, quantum physics

It’s ten times more stable and could lead to a quantum computing breakthrough.

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Nov 9, 2016

Trickling electrons

Posted by in categories: particle physics, quantum physics

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics.

Flowing water from a tap feels like a homogeneous medium – it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass?

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Nov 9, 2016

A Zeptosecond Stopwatch for The Microcosm

Posted by in categories: particle physics, quantum physics

For the first time ever, laser physicists have recorded an internal atomic event with an accuracy of a trillionth of a billionth of a second.

When light strikes electrons in atoms, their states can change unimaginably quickly. Laser physicists at LMU Munich and the Max Planck Institute of Quantum Optics (MPQ) have now measured the duration of such a phenomenon – namely that of photoionization, in which an electron exits a helium atom after excitation by light – for the first time with zeptosecond precision. A zeptosecond is a trillionth of a billionth of a a second (10−21 s). This is the first absolute determination of the timescale of photoionization, and the degree of precision achieved is unprecedented for a direct measurement of the interaction of light and matter.

When a light particle (photon) interacts with the two electrons in a helium atom, the changes take place not only on an ultra-short timescale, but quantum mechanics also comes into play. Its rules dictate that either the entire energy of the photon is absorbed by one of the electrons, or the energy is distributed between them. Regardless of the mode of energy transfer, one electron is ejected from the helium atom. This process is called photoemission, or the photoelectric effect, and was discovered by Albert Einstein at the beginning of the last century. In order to observe what occurs, you need a camera with an incredibly fast shutter speed: The whole process, from the point at which the photon interacts with the electrons to the instant when one of the electrons leaves the atom, takes between 5 and 15 attoseconds (1 as is 10–18 seconds) as physicists have worked out in recent years.

Continue reading “A Zeptosecond Stopwatch for The Microcosm” »

Nov 8, 2016

Close to absolute zero, electrons exhibit their quantum nature

Posted by in categories: particle physics, quantum physics

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics.

Flowing water from a tap feels like a homogeneous medium — it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass?

The hourglass analogy is very appropriate for the scanning tunnelling microscope, where a thin, pointed tip scans across the surface of a sample without actually touching it. A tiny current flows nevertheless, as there is a slight probability that electrons “tunnel” from the pointed tip into the sample. This tunnelling current is an exponential function of the separation, which is why the pointed tip is located only a few Ångström (a ten millionth of a millimetre) above the sample.

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Nov 7, 2016

Tangled Up in Spacetime

Posted by in category: quantum physics

Hundreds of researchers in a collaborative project called “It from Qubit” say space and time may spring up from the quantum entanglement of tiny bits of information.

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Nov 7, 2016

Can Quantum Physics Explain Consciousness?

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

A new approach to a once-farfetched theory is making it plausible that the brain functions like a quantum computer.

The mere mention of “quantum consciousness” makes most physicists cringe, as the phrase seems to evoke the vague, insipid musings of a New Age guru. But if a new hypothesis proves to be correct, quantum effects might indeed play some role in human cognition. Matthew Fisher, a physicist at the University of California, Santa Barbara, raised eyebrows late last year when he published a paper in Annals of Physics proposing that the nuclear spins of phosphorus atoms could serve as rudimentary “qubits” in the brain—which would essentially enable the brain to function like a quantum computer.

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Nov 5, 2016

D-Wave Names Jeremy Hilton as Senior Vice President, Systems, Founder Geordie Rose Now Special Advisor

Posted by in categories: computing, engineering, quantum physics

Congrats geordie rose and jeremy hilton ; d-wave ROCKS!

News posting on T-Net)


Burnaby, BC, November 4, 2016—(T-Net)—D-Wave Systems Inc., the world’s first quantum computing company, announced the promotion of Jeremy Hilton to senior vice president, systems, with responsibility for driving the company’s quantum processor and systems research and engineering functions.

Continue reading “D-Wave Names Jeremy Hilton as Senior Vice President, Systems, Founder Geordie Rose Now Special Advisor” »

Nov 5, 2016

New Distance Record Offers Preview of Everyday Quantum Encryption

Posted by in categories: encryption, quantum physics

AWESOME!

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