Yes, it is possible to create a bus or a communication network that can connect different quantum computers together. This concept is often referred to as a quantum network or a quantum internet. The idea behind a quantum network is to enable the transfer of quantum information between different quantum computing systems, allowing them to work together and perform distributed computations.
Building a quantum network presents several challenges due to the fragile nature of quantum information and the requirements of maintaining quantum coherence. However, researchers are actively working on developing the necessary technologies and protocols to make quantum networks a reality.
One approach to creating a quantum network involves using quantum repeaters. Quantum repeaters are devices that can extend the distance over which quantum information can be transmitted while preserving its quantum state. They work by breaking the transmission into shorter segments and entangling the qubits in each segment with fresh qubits at intermediate stations. This process allows quantum information to be transmitted over longer distances, overcoming the limitations of noise and decoherence.
Another important aspect of a quantum network is the development of quantum protocols for tasks such as quantum key distribution (QKD), which enables secure communication using quantum principles. QKD allows the exchange of encryption keys encoded in quantum states, providing a high level of security that is not possible with classical communication protocols.
In recent years, there have been significant research efforts towards building quantum networks. For example, quantum communication links have been established between different research labs, and quantum satellites have been used to demonstrate long-distance quantum communication.
While the development of a fully functional quantum network is still a complex and ongoing research endeavor, the vision of connecting multiple quantum computers together holds great promise for distributed quantum computing, secure communication, and other applications in the future.