A network where data transmission is completely safe from hackers can become a reality with the help of the phenomenon of quantum entanglement. A group of scientists from Germany recently demonstrated that atoms 33 kilometers apart are entangled on an optical fiber, advancing research into more secure quantum networks.
Quantum entanglement is an incredible quantum phenomenon. When two or more particles interact with each other, they will synthesize into a “whole property”. The characteristics of the particles can no longer be described separately, and the system can only be viewed as a whole. With this way, we can learn the state of another particle; even more strangely, changing some properties of one particle will immediately affect its partners, no matter how far apart they are.
The speed at which this information is “transmitted” is faster than the speed of light, and even Einstein found it excessive, so he described it as “spooky action at a distance.”
In recent decades, the phenomenon of quantum entanglement has been confirmed in experiments, and scientists have also used this strange property to achieve the purpose of fast data transmission over long distances.
Recently, a research team from the University of Munich and Saarland University in Germany has set a record for the longest distance quantum entanglement of two atoms through an optical fiber.
The team first separated two rubidium atoms with a 700-meter fiber, and then the fiber was extended up to 33 kilometers through other lines, and then the rubidium atoms were excited with laser pulses to emit photons that were quantum entangled with the rubidium atoms, and then the photons
Sending along the fiber-optic cable and meeting at the receiving station, the researchers then measured the photons to entangle them—and because they were entangled with the original rubidium atoms, so did the rubidium atoms.
Although there have been previous records of photons entangled at longer distances, the new study sets the distance at which two atoms are entangled on an optical fiber. The team said this is an important step in realizing quantum networks, and more importantly, the research shows that they can use existing fibers.
The infrastructure is operational, and should be able to be combined with satellite technology later as well.
The new paper was published in the journal Nature.