Toshiba researchers succeeded in building a 600-kilometer-long quantum network of optical fibers that enables safe and unhackable transmission of quantum data on a large scale and long distances. This technology can affect secure data transmission between cities and even countries in the future.
Researchers at Toshiba’s research and development department in Cambridge, England have shown how quantum bits, or qubits, can be moved along a path of several hundred kilometers of optical fibers without losing fragile information. The technology used can stabilize common environmental fluctuations in optical fibers and prevent damage to sensitive quantum particles containing information. The result of the mentioned research can be very important in the development of the quantum network in large dimensions and the next generation of the Internet.
The quantum internet will consist of a huge network of interconnected quantum devices that can provide possibilities far beyond today’s web. Creating stable and unhackable connections will be one of its benefits. Also, building a cluster of devices connected to each other with processing power far beyond classical computers is one of the most important advantages of the next generation of the Internet.
But quantum devices need to exchange qubits to communicate with each other, which will be very sensitive and fragile. Finding a way to transfer information without damaging the qubits has fascinated many scientists for many years. The use of optical fibers to transport qubits has been tested in the past, and the results have had an impressive success rate. But the main problem was the impossibility of using optical fiber for long distances, because when the conditions of the environment around the fiber, such as temperature, change in volume, it increases the possibility of data loss.
In a recent experiment by Toshiba researchers, a new method called two-channel stability was used to solve problems related to changing environmental conditions around optical fibers. In this method, two signals with different wavelengths are sent into the fiber. The first signal is used to fix the environmental variables and identify them, and the second signal is sent with the same wavelength as the qubits to better equalize the conditions. In simple words, using two signals with different wavelengths can eliminate the environmental interference caused by the fiber itself.
Toshiba has used the result of recent research to build quantum encryption and create unhackable communication networks. In such networks, users can exchange confidential information in complete security, which can be very useful in businesses such as banks or hospitals. Instead of using mathematical complexity, quantum cryptography uses physical constraints to defend against attacks, and ordinary computers will not be able to break the ciphers at all.
Building a 600 km unhackable quantum network with optical fiber
