Toshiba engineers have managed to send quantum information via optical fiber length of 600 kilometers and set a new record. It is reported on the website of the Japanese corporation.
The report says that thanks to a new technology that stabilizes oscillations in the environment, the specialists managed to demonstrate the transfer of quantum bits (qubits) at a distance of hundreds of kilometers. On the basis of this invention scientists can develop a new generation network, through which it will be possible to safely transmit data between cities and entire countries.
The information transferred by the optical fiber is ciphered with the help of technology of quantum distribution of keys (QKD). Engineers noted that the protocol uses quantum networks to create encryption keys, which are virtually immune to hacking. Both parties will be alerted if the network is penetrated. 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 small network lengths. Small changes in the environment, like temperature fluctuations, can cause the cable to expand or contract and destroy information. To reduce the impact of the environment, Toshiba engineers developed a method called dual-band stabilization. In this case, data is sent via two signals – the first compensates for rapidly changing fluctuations and the second is used to fine-tune the phase. In this way, it is possible to transmit data up to 600 kilometers in quality.
“Thanks to the new methods we have developed, further extending the communication distance for QKD is still possible, and our solutions can also be applied to other quantum communication protocols and applications,” noted Toshiba Europe researcher Mirko Pittaluga. The company plans to build a secure superfast backbone connecting London, Paris, Brussels, Amsterdam and Dublin.
A cubit is the smallest unit of information in a quantum computer, used for quantum computing. At the end of May, Google announced that it would build a quantum computer for several billion dollars. The new device will make it possible to perform calculations that a modern computer would take 10,000 years to perform in three and a half minutes.