Research successfully establishes the first multipoint quantum network based on quantum entanglement

Research published April 16 in the journal Science has created the world’s first multipoint quantum network, connecting three quantum processors. More importantly, the team has shown for the first time how different network protocols can cooperate to transmit data within a quantum network.

For the past decade, scientists have worked on the first step in building a quantum network – connecting two quantum processors. Now, this study begins to take the next step – establishing multipoint connections.

The study uses both physical connections and contactless connections based on quantum entanglement, and successfully demonstrates that the two protocols work together. The researchers say this is an important foundation for connecting more types of protocols and scaling up quantum networks in the future.

A network protocol is a rule, standard or convention established for exchanging data in a computer network. Each member connected to the network follows such a convention in order to pass information correctly. During the development of the network, scientists have developed many protocols for different purposes, so it is also important to have principles of communication between the protocols so that they operate in unison.

This research, led by Delft University of Technology in the Netherlands, demonstrates for the first time a multipoint connected quantum network. This network contains three quantum processors, also known as three nodes, located in the same building. The middle node is called Bob, and the other two nodes are called Alice and Charlie. bob and Alice and Bob and Charlie use physical connections to each other, and allow all nodes to establish quantum entanglement-based connections to each other as well. Quantum entanglement is an amazing physical phenomenon in which two particles form a close connection across space and achieve synchronization.

Bob is equipped with an additional quantum bit to record the state of the network connection. After Bob and Alice and Bob and Charlie have each established a connection, one way they have tried is to perform a series of quantum operations on Bob to convert these connections into a connection between Alice and Charlie. They also tried another approach, which involved a series of quantum operations on Bob to form a quantum entanglement connection between the three nodes.

The major breakthrough in this conceptual demonstration, the study says, is the establishment of a set of protocols with “flag” signals that could form the basis for future communication between different types of protocols within large-scale quantum networks.

Once the connections are established, we are able to preserve the entangled states and protect them from noise,” said Sophie Hermans, a member of the research team. This means that, in principle, we can use these states for quantum key distribution, quantum computing or other quantum protocols.”

Ronald Hanson, the study’s leader, said this research demonstrates the first multipoint network based on quantum entanglement, providing a testbed for developing quantum network hardware, software and various transmission protocols.