NASA researchers have managed to teleport information about the quantum state of a photon, a particle of light, 25 kilometers of optical fiber to a ‘memory bank’ glass.
The previous record in the optical fiber was 6 kilometers . This complex phenomenon of quantum teleportation could have implications for cryptography, which is the transmission safely, including communications between Earth and spacecraft.
” We can print the state of a system on another system, even when the two are far apart, “said Francesco Marsili, engineer microdevices the Jet Propulsion Laboratory (JPL) in Pasadena. “The use of this effect in communications could help build a network of intrinsically safe space communications, ie, communications channels that can not be hacked.”
Marsili and colleagues at the National Institute of Standards and Technology (NIST), develop devices that can detect single particles of light, called developed photons.
“It is difficult to detect a single photon, so you need to make a sensitive detector “he said. “Here at JPL, in collaboration with NIST, we have developed the most sensitive in the world detector.”
How quantum teleportation works is complicated, but an analogy to the principle in underpinning it may help: Say there are two people, Alice and Bob. Alice wants Bob to have a photon is in the same “state” that his photon, photon will call P. For the sake of this analogy, let’s pretend that the “state” is a color, and the photon P is Yellow. A third person named Charlie sends two entangled photons, photon to photon B Alice and Bob, who behave as if they were part of the same whole. Both of these photons start are shown in blue.
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“In an entangled system, each part is connected together in a fundamental way, so that any action taken in one part of the entangled system has an effect on the entire entangled system, “Marsili said.
The two photons Alice, P, which is yellow, and A, which is blue, “collide”. Alice measures the photons as they annihilate each other. Although P and A are destroyed in the accident, the yellow color of P. Since A and B photons are entangled photons, the yellow color is “teleported” to B. But in order to do that the photon is preserved B becomes yellow, like the photon P was originally, Alice needs to send Bob two bits of information to B using the “classic” way -. for example, by sending pulses of light through an optical fiber
“When Alice measures the state of the photon, Bob photons change state too, as if a interrupto r is activated,” Marsili said. “But Bob can not know unless Alice to send bits of classical information.” Bob does not know his photon has changed to yellow without this additional information.
The quantum teleportation does not mean someone can jump from New York to San Francisco instantaneously , but seems like science fiction in the sense that the state of a particle (photon P) is destroyed in one place, but playing in another remote system (photon B) without the two particles have never interacted.
Another piece essence of this story is that Bob has a specific crystal, which serves as a memory bank to store their entangled photon and serve as recipient of the quantum state.
The researchers reached a record distance of 25 kilómetetros between “Alice” and “Bob” by ultrasensitive detectors developed by JPL and NIST. “Reaching this distance would not have been possible without these detectors” , said Félix Bussières at the University of Geneva, lead author of the study.
The quantum teleportation can be used to make that systems like bank accounts safer through longer distances. This is also important for preventing attacks on communication channels in space.
“If you’re communicating with astronauts on Mars, you should keep hackers break the encrypted channel and give them information false, “Marsili said.
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