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 New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology

nachricht Light rays from a supernova bent by the curvature of space-time around a galaxy
21.04.2017 | Stockholm University

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: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>