Toshiba engineers managed to send quantum information over an optical fiber 600 kilometers long and set a new record. This is reported on the website of the Japanese corporation.
The report says that thanks to a new technology that stabilizes fluctuations in the environment, experts were able to demonstrate the transmission of quantum bits (qubits) at a distance of hundreds of kilometers. Based on this invention, scientists can develop a new generation network that can safely transfer data between cities and entire countries.
The information transmitted over the fiber is encrypted using quantum key distribution (QKD) technology. The engineers noted that to create encryption keys, the protocol uses quantum networks that are virtually immune to hacking. In case of penetration into the network, both parties will be warned. This means that users and corporations can share valuable data over vast distances without fear of leakage.
Until recently, the transmission of qubits over fiber-optic networks was limited to a small network length. Small changes in the environment, such as temperature fluctuations, can cause the cable to expand or contract and destroy information. To reduce the impact of the environment, Toshiba engineers have developed a method called dual-band stabilization. In this case, the data is sent via two signals — the first compensates for rapidly changing fluctuations, the second is used for more precise phase tuning. Thus, it is possible to transmit high-quality data at a distance of up to 600 kilometers.
"Thanks to the new methods we have developed, further expansion of the communication distance for QKD is still possible, and our solutions can also be applied to other quantum communication protocols and applications," said Mirko Pittaluga, a researcher at Toshiba Europe. The company plans to build a safe super-high-speed highway connecting London, Paris, Brussels, Amsterdam and Dublin.
A qubit is the smallest unit of information in a quantum computer used for quantum computing. At the end of May, Google announced that it would create a quantum computer for several billion dollars. The new device will allow you to perform calculations that a modern computer will spend 10 thousand years, in three and a half minutes.
Andrey Stavitsky