To enable quantum computers to communicate and exchange, a crucial step is the establishment of a network which would be similar, in principle, to that of the Internet. However, the physical properties of quantum particles complicate the task of researchers a little. Toshiba has, however, succeeded in designing a stable quantum network that operates 600 kilometers away. To do this, teams from a UK-based laboratory relied on optical fiber.
A stable quantum communication network
Communication at the quantum level is done through the exchange of qubits, these are particles that store information at the quantum level. However, they are very fragile and therefore require special treatment to facilitate their journey without degrading the message. In fact, it only takes a tiny change in temperature to make them unstable.
To avoid this, the researchers developed a promising new method called ” dual band stabilizationWhich consists in sending two signals with different wavelengths which cancel out the effects of the external environment. It is a kind of shock absorber that protects the qubits during the journey and which therefore, according to Toshiba, would have worked on a journey of 600 kilometers.
Improvements are still possible
This technology has been tested by distributing quantum keys or QKD, a cryptographic protocol deemed inviolable which is therefore particularly coveted. “With the new techniques we have developed, further extensions of the communication distance for QKD are still possible and our solutions can also be applied to other quantum communication protocols and applications,Said Mirko Pittaluga, research scientist at Toshiba Europe.