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Re: Physicists set quantum record by using photons to carry messages from electrons almost 2 kilometers apart

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Sam Wormley <swormley1@gmail.com> wrote:
> Physicists set quantum record by using photons to carry messages from 
> electrons almost 2 kilometers apart
>> http://phys.org/news/2015-11-physicists-quantum-photons-messages-electrons.html
> 
> 
>> Photons can have a vertical or horizontal orientation (known as
>> polarization), which can be referenced as a 0 or a 1, as in digital
>> computer programming. But if they change en route, the connection to
>> the correlated electron is lost.
>>
>> This information can be preserved in another way, Yu said. He created
>> a time-stamp to correlate arrival time of the photon with the
>> electron spin, which provided a sort of reference key for each photon
>> to confirm its correlation to the source electron.
>>
>> To eventually entangle two electrons that had never met over great
>> distances, two photons, each correlated with a unique source
>> electron, had to be sent through fiber optic cables to meet in the
>> middle at a "beam splitter" and interact. Photons do not normally
>> interact, just two flashlights beams passing through one another, so
>> the researchers had to mediate this interaction called the
>> "two-photon interference."
>>
>> To ensure the two-photon interference, they had another issue to
>> overcome. Photons from two different sources have different
>> characteristics, like color and wavelength. If they have different
>> wavelengths, they cannot interfere, Yu said. Before traveling along
>> the fiber optic cable, the photons passed through a "quantum
>> down-converter," which matched their wavelengths. The down-converter
>> also shifted both photons to a wavelength that can travel farther
>> within the fiber optic cables designed for telecommunications.
 
Were they nonomessages?

Is it sustainable?

-- 
Jim Pennino

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Physicists set quantum record by using photons to carry messages from electrons almost 2 kilometers apart Sam Wormley <swormley1@gmail.com> - 2015-11-25 14:24 -0600
  Re: Physicists set quantum record by using photons to carry messages from electrons almost 2 kilometers apart jimp@specsol.spam.sux.com - 2015-11-25 20:43 +0000

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