In his previous work, Stanford physicist Leo Yu has entangled photons with electrons through fiber optic cables over a distance of several feet. Now, he and a team of scientists, including Professor Emeritus Yoshihisa Yamamoto, have correlated photons with electron spin over a record distance of 1.2 miles (1.93 kilometers).
"Electron spin is the basic unit of a quantum computer," Yu said. "This work can pave the way for future quantum networks that can send highly secure data around the world."
To do this, Yu and his team had to make sure that the correlation could be preserved over long distances – a key challenge given that photons have a tendency to change orientation while traveling in optical fibers.
Let's see the NSA surveille ansibles.
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Physicists Set Quantum Record by Using Photons to Carry Messages From Electrons 2 Kilometers Apart
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(Score: 2) by frojack on Saturday November 28 2015, @05:19AM
This shit is so new that reading about it over the internet is like reading a telegraph report of Marconi's 1901 transatlantic radio signal.
Two kilometers. We marvel!
Its probably how we will communicate with Mars in real time.
No, you are mistaken. I've always had this sig.
(Score: 2) by takyon on Saturday November 28 2015, @05:29AM
The record distance for quantum teleportation is 143 km (89 mi). [wikipedia.org]
Eventually these capabilities will work ground-to-orbit [nasa.gov]. Which could be useful for... something.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Yog-Yogguth on Saturday December 05 2015, @07:59AM
I'm out of modpoints but wow yes! (It would have been a +1 Insightful from me). I'm almost embarassed I hadn't thought about it that way until you pointed it out.
Bite harder Ouroboros, bite! tails.boum.org/ linux USB CD secure desktop IRC *crypt tor (not endorsements (XKeyScore))
(Score: 2) by Tork on Saturday November 28 2015, @05:31AM
🏳️🌈 Proud Ally 🏳️🌈
(Score: 2) by Non Sequor on Saturday November 28 2015, @01:32PM
The article is mistaken, no message is transmitted over 2 kilometers. The deal with this is, you can use the entangled photons as part of a protocol that results in both parties sharing a one-time pad, that they can use to encrypt messages shared over a classical communications channel. You can't send messages through the entanglement.
There isn't really a breakthrough here, this is just physicists testing more variations on the setup for using quantum entanglement for quantum key distribution.
Write your congressman. Tell him he sucks.
(Score: 2) by wonkey_monkey on Saturday November 28 2015, @01:38PM
Does the change in spin happen instantaneously, or does it take however long it takes for light to travel for the changes to propagate?
Last I heard, they (boffins) reckoned it happened at least 10,000 times faster than light would have taken to travel.
but why wouldn't just the fact that the spin is changing be a way of transmitting information? (i.e. morse code...?)
Because it's not information. If you put a magical coin (paired with one of your own) in an envelope and post it to a friend, then you sit and watch your own magical coin, and see it flip itself spontaneously to heads, all you know is that the other coin has flipped to tails. But that does not and can not tell you anything about what's happening in the environs of the other coin. You can't know if it was your friend who flipped it; you can't know if he will now take whatever action you both previously agreed upon based on the coin toss.
In a sense, the coin's present location (presumably at your friend's address) is entirely meaningless, as far as the toss is concerned. No information can't travel from there to here because (in some slightly abstract way that I've only just thought of), the coin isn't there at all. Nothing at the coin's location can influence the result of the toss. It might as well be right there in the room with you (and, in fact, in another slightly abstract sense, it is - it's entangled with the coin you've got).
systemd is Roko's Basilisk
(Score: 2) by wonkey_monkey on Saturday November 28 2015, @02:06PM
To extend my location metaphor a little further, imagine that the two entangled coins have a "location" of their own, distinct from your location and your friend's location. When the coin is tossed, information flows from the coin's (or coins') location to both your location and your friend's location - but it's one-way. Information can't flow from your location to your friend's location via the coins' location.
systemd is Roko's Basilisk
(Score: 0) by Anonymous Coward on Sunday November 29 2015, @03:55AM
Here is a better analogy that I thought of years back. Imagine that you and a friend each had a device each with two lights. Either light one or light two on your device would be on and the light would change at random with random timing. The light may change in 1 second or two seconds or three seconds or whatever, the amount of time it changes is random except that it's always a whole integer. The same is true with the other device. There is no correlation between your light and the light on the other device except that the integer change increments are in sync. So in exactly one second either the light on one device would change or the light on both devices would change. In exactly two seconds either the light on one device would change or the light on both devices would change. Each device has a button. If you or the other person (but not both) press and hold your button the only thing you know is that the light on your device would be opposite the light on the other device the next time both lights would otherwise change randomly (whether or not they would otherwise be in sync or not). But if you are both holding the buttons down at the same time then the lights would always be in sync the next time both lights would otherwise change simultaneously. If no one is holding the button then both lights change at random (may stay the same or change within increments of a second). In real life take the limit as that second increment goes to zero. From the perspective of an observer that can see both sets of lights at once it's obvious there is a correlation between the buttons and the lights. From the perspective of someone that can only see one set of lights at once there is no way to communicate with the other.
(Score: 0) by Anonymous Coward on Sunday November 29 2015, @12:09PM
Actually the above analogy may have flaws. Make it so that the current relative relationship of both lights stays the same when one button is being held. So if no buttons are being held the relationship between both sets of lights could be that both lights are the same or different and that relationship could change. If one button is held the relationship stays the same as it was just before that button was pressed. The lights change at random but if they were both opposite just before the button gets held they remain opposite. If they were both the same just before the button gets held they remain the same. If both buttons are held it's as though no button is being pressed.
(Score: 0) by Anonymous Coward on Sunday November 29 2015, @08:11PM
Also neither light has to change when a second elapses. A second could elapse and either no light changes or one light changes or both lights change. Just that when the button is being held their relative positions remain the same. If light 1 on box A and light 2 is on on box B are on at the time the button is pressed and held then the opposite lights will always be on. A second could elapse and either neither of the lights change or both of the lights change. From the perspective of the person not holding the button they can't tell if the light is changing or staying the same because it's the same as the opposite light or opposite it and they have no way of telling if it's remaining the same or opposite the other light due to the button being held since they don't even know if it's the same or opposite the other light. Even a neutral observer that can observe both sets of lights at the same time and not the buttons can't necessarily tell if the lights are remaining the same or opposite due to a button being held or if it's just a coincidence (but enough coincidences can amount to a high statistical probability to a neutral observer that can see both sets of lights at the same time and not the buttons but not to someone that can only see only one set of lights and has control of the button for that set of lights) but he does know that whenever one button is being held the relative positions of the lights always remain the same whenever he is able to see both sets of lights and both buttons.
(Score: 3, Funny) by aristarchus on Saturday November 28 2015, @06:58AM
What does this:
have to do with anything? Doesn't really matter what photons do in your pathetic glass fibers, once we have the magical quantum communication without the need for media! I laugh at your photon spin! Mine has already shifted, in accordance with my fiendish plan to communicate without an ISP! Igor! Bring me the quantum helmet!!!
(Score: 2) by dmc on Sunday November 29 2015, @03:17AM
Last I checked you had to be a diplomat to be magically immune.