The Raelian Movement
for those who are not afraid of the future : http://www.rael.org
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Quantum Networks Advance With Entanglement of Photons, Solid-State Qubits
http://www.sciencedaily.com/releases/2010/08/100804133358.htm
ScienceDaily (Aug. 5, 2010) — A team of Harvard physicists led by
Mikhail D. Lukin has achieved the first-ever quantum entanglement of
photons and solid-state materials. The work marks a key advance toward
practical quantum networks, as the first experimental demonstration of
a means by which solid-state quantum bits, or "qubits," can
communicate with one another over long distances.
Quantum networking applications such as long-distance communication
and distributed computing would require the nodes that process and
store quantum data in qubits to be connected to one another by
entanglement, a state where two different atoms become indelibly
linked such that one inherits the properties of the other.
"In quantum computing and quantum communication, a big question has
been whether or how it would be possible to actually connect qubits,
separated by long distances, to one another," says Lukin, professor of
physics at Harvard and co-author of a paper describing the work in the
journal Nature.
"Demonstration of quantum entanglement between a solid-state material
and photons is an important advance toward linking qubits together
into a quantum network."
Quantum entanglement has previously been demonstrated only with
photons and individual ions or atoms.
"Our work takes this one step further, showing how one can engineer
and control the interaction between individual photons and matter in a
solid-state material," says first author Emre Togan, a graduate
student in physics at Harvard. "What's more, we show that the photons
can be imprinted with the information stored in a qubit."
Quantum entanglement, famously termed "spooky action at a distance" by
a skeptical Albert Einstein, is a fundamental property of quantum
mechanics. It allows one to distribute quantum information over tens
of thousands of kilometers, limited only by how fast and how far
members of the entangled pair can propagate in space.
The new result builds upon earlier work by Lukin's group to use single
atom impurities in diamonds as qubits. Lukin and colleagues have
previously shown that these impurities can be controlled by focusing
laser light on a diamond lattice flaw where nitrogen replaces an atom
of carbon. That previous work showed that the so-called spin degrees
of freedom of these impurities make excellent quantum memory.
Lukin and his co-authors now say that these impurities are also
remarkable because, when excited with a sequence of finely tuned
microwave and laser pulses, they can emit photons one at a time, such
that photons are entangled with quantum memory. Such a stream of
single photons can be used for secure transmission of information.
"Since photons are the fastest carriers of quantum information, and
spin memory can robustly store quantum information for relatively long
periods of time, entangled spin-photon pairs are ideal for the
realization of quantum networks," Lukin says. "Such a network, a
quantum analog to the conventional internet, could allow for
absolutely secure communication over long distances."
Lukin and Togan's co-authors on the Nature paper are Yiwen Chu, Alexei
Trifonov, Jeronimo Maze, and Alexander S. Zibrov, all at Harvard;
Liang Jiang of Harvard and the California Institute of Technology;
Lilian I. Childress of Harvard and Bates College; M.V. Gurudev Dutt of
Harvard and the University of Pittsburgh; A.S. Sorensen at the
University of Copenhagen; and Phillip R. Hemmer of Texas A&M
University. The work was supported by the Defense Advanced Research
Projects Agency, the Harvard-MIT Center for Ultracold Atoms, the
National Science Foundation, the National Defense Science &
Engineering Graduate Fellowship, and the Packard Foundation.
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"Ethics" is simply a last-gasp attempt by deist conservatives and
orthodox dogmatics to keep humanity in ignorance and obscurantism,
through the well tried fermentation of fear, the fear of science and
new technologies.
There is nothing glorious about what our ancestors call history,
it is simply a succession of mistakes, intolerances and violations.
On the contrary, let us embrace Science and the new technologies
unfettered, for it is these which will liberate mankind from the
myth of god, and free us from our age old fears, from disease,
death and the sweat of labour.
Rael
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