Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A quantum computer breakthrough and dark matter stars

30.11.2007
Highlights in this issue: A quantum computer breakthrough and dark matter stars.

Quantum Computer Breakthrough

Chao-Yang Lu, Daniel E. Browne, Tao Yang, and Jian-Wei Pan Physical Review Letters (forthcoming) and B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James , A. Gilchrist, and A. G. White

Physical Review Letters (forthcoming)

Two research groups have independently managed to experimentally solve a mathematical problem with light-based quantum computers. The simultaneous achievements appear to be the first experimental demonstrations of true (though rudimentary) quantum mechanical computations. Both groups manipulated quantum mechanically entangled photons to calculate the prime factors of the number 15.

Although the physicists could have gotten the answer to the problem much more easily by querying an average elementary school child, the method both groups used involved a quantum mechanical approach commonly known as Shor's algorithm. Previous theoretical work has shown that the algorithm could potentially crack cryptographic codes that are practically unbreakable with non-quantum mechanical (classical) computers.

While there's no great need to factor numbers as small as 15, the research demonstrates that quantum computation is feasible with existing technology and could in principle be scaled up to tackle problems that would take longer than the age of the universe to solve with any classical computer, but would require only minutes on a quantum computer.

In addition to factoring large numbers and solving other challenging mathematical problems, quantum computers based on the work of these two groups could help model quantum mechanical problems in physics and chemistry (see http://xxx.lanl.gov/ftp/arxiv/papers/0710/0710.0278.pdf for an example of a quantum simulator experiment by C.-Y. Lu et al.), and lead to ultra high speed searching algorithms.

Chao-Yang Lu and his group are currently expanding on their work by trying to manipulate larger numbers of quantum bits. In the long run, they plan to add quantum memory to their quantum computers, which could further increase the number of photons they can control. In addition, because the loss of photons is a huge problem for light-based quantum computation, they are working on some basic quantum codes that can protect the quantum information from photon loss error. These sorts of issues are crucial in the effort to scale up photonic quantum computation. - JR

Dark Matter Stars

Douglas Spolyar, Katherine Freese, and Paolo Gondolo Physical Review Letters (forthcoming)

Before stars were fueled by nuclear fusion, they may have been fueled by dark matter. Researchers have theorized that "Dark Stars" may have been supported by the huge release of energy from dark matter annihilation (i.e. the release of energy that comes when matter and antimatter encounter each other) in the early universe. The physicists from UC Santa Cruz, UM Ann Arbor, and the University of Utah believe that despite many theories stating otherwise, dark matter did have an effect on the first stars in the universe.

The release of energy from dark matter/anti-dark matter annihilation may have prevented the first proto-stars from collapsing and beginning fusion, but in turn could have heated a star¿s core enough to support it. This would change the time scale of the formation of second generation stars, the appearance of elements like nitrogen, carbon, and oxygen in our universe, and other aspects of stellar evolution.

Products of the annihilation, such as neutrinos, gamma-rays, or antimatter may make these dark stars or their remnants detectable. Although stars composed of dark matter are likely to be much dimmer than normal stars, they may produce some light. The next step for researchers will be to determine how much visible light the dark stars give off, and how long they survive. Dark stars may have died out millions of years ago, or they may still exist today.

The idea of dark stars relies on the Lightest Super symmetric Particle (LSP), a highly favored candidate for particles that make up dark matter. The properties of the LSPs are consistent with current information about dark matter in the universe. Many physicists are hopeful that new experiments in particle colliders will soon yield more discoveries on the nature of dark matter, and perhaps offer insight into the possibility of dark stars in the early universe. - CC

Contact: James Riordon
American Physical Society
riordon@aps.org
301-209-3238

James Riordon | American Physical Society
Further information:
http://www.aps.org

More articles from Physics and Astronomy:

nachricht Comet or asteroid? Hubble discovers that a unique object is a binary
21.09.2017 | NASA/Goddard Space Flight Center

nachricht First users at European XFEL
21.09.2017 | European XFEL GmbH

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>