Quantum information is transmitted from one side of a simple quantum network to the other and passes through intermediate network nodes without impact.
May 25, 2022
Quantum networks can use so-called quantum entanglement to teleport information between unconnected nodes. This is an important step in building a super-secure quantum internet.
Objects that share entanglement have linked properties. Entanglement is at the heart of the quantum internet proposal, which can significantly improve privacy compared to current internet systems. One idea is to build a network of connected qubits or qubits that are intertwined with qubits elsewhere in the network rather than directly linked adjacent nodes. However, the entanglement of these network qubits has so far been demonstrated only with directly connected qubits.
Ronald Hanson The Delft University of Technology in the Netherlands and his colleagues have built a simple network containing numerous diamond-based qubits located on three nodes called Alice, Bob, and Charlie. There was no direct connection between Alice and Charlie, only indirect links that each shared with Bob. However, Alice and Charlie shared entanglement. In other words, it is impossible to measure one’s information without changing one’s state.
As Charlie’s quantum state changed, so did Alice’s state. That is, the information was “teleported” without passing through Bob.
“It’s really teleporting like a science fiction movie,” says Hanson. “The state, or information, actually disappears on one side and is displayed on the other side because it hasn’t moved the space between them. [the data] You won’t get lost. “
Although it was theoretically possible to use entanglement in this way for decades, node qubits include “memory” qubits that can hold quantum states for longer than standard qubits. Because it is, it has been successfully proven only here.
Even if you build a quantum Internet network or two nodes in the network change at the same time, it will not be faster than a conventional system. This is because users who share information about network changes must share it via traditional non-quantum communication. However, Quantum Web provides truly private features such as eavesdropping prevention communications and data servers that cannot detect the source of the data you are processing. “Probably a lot [applications] We still have to find out, “says Hanson.
Hanson and his team first built and tested a quantum network in which non-adjacent nodes are intertwined, while other teams used different types of quantum communication, including those that use intertwined photons. I’m experimenting.
“It’s very important to try these types of experiments on different platforms,” he says. Charles Addams At Durham University in the United Kingdom. “Which technology [going to succeed] – Maybe it will be some kind of hybrid of different technologies. “
Journal reference: Nature, DOI: 10.1038 / s41586-022-04697-y
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