A team of scientists from the United States was able to prove the possibility of instantaneous transmission of a quantum state over long distances. The researchers succeeded in transmitting the quantum state over 44 km with an accuracy of more than 90% over fiber-optic networks, similar to those that form the basis of the existing Internet.
Instantaneous transmission of a quantum state, or quantum teleportation, is carried out using entangled qubits. By “interweaving” three qubits, one can force one particle to assume the state of another through their mutually entangled partner. As ScienceAlert explains, it’s like turning one particle into another, teleporting it a distance in the blink of an eye.
The unstable nature of quantum information makes it difficult to transmit entangled qubits over long distances without interference: Long optical fibers mean more noise. In a joint experiment by Fermilab, AT&T, California Institute of Technology, Harvard University, NASA’s Jet Propulsion Laboratory and the University of Calgary, scientists were able to carry out quantum teleportation at a distance of 44 kilometers. Today, this is the limit on how far scientists can send a quantum state.
“We are very proud to have reached this milestone in the development of robust, high-performance and scalable quantum teleportation systems. The results will be further enhanced by a system upgrade that we expect to be completed by the second quarter of 2021,” Maria Spyropoulou said, professor of physics at California Institute of Technology.
In future experiments, scientists are going to set a new record for teleportation distance and for the number of entangled qubits.
“With this experiment, we are laying the groundwork for the construction of an urban quantum network in the Chicago area,” said Panagiotis Spentzouris, Fermilab’s quantum science program manager.
In the summer of 2020, a plan was presented in Chicago to create a quantum Internet in the United States, which should become not only faster, but also safer than the classical one.
The Illinois Express Quantum Network is being developed by Fermilab in collaboration with Argonne National Laboratory, California Institute of Technology, Northwestern University and industry partners.
For now, researchers believe that quantum internet networks will act as specialized extensions of the classic internet, rather than a complete replacement for it.