Introduction to Quantum Networks

Introduction to Quantum Networks

A quantum network is a communication network that enables long-distance and secure exchange of quantum keys or quantum information between users. This network is capable of providing quantum services to different types of users in various locations and with different access methods (optical fiber, wireless, satellite, etc.). In general, channel attenuation and noise are considered challenges for long-distance communications. To solve this issue in long-distance transmission of a classical signal, classical repeaters are used. Classical repeaters receive a weak, noisy signal, amplify and error correct it, and reproduce a strong, clean signal, thereby overcoming the challenge of channel attenuation and noise. However, quantum mechanics principles such as the no-cloning theorem prevent direct implementation of such operations in quantum networks. Therefore, quantum networks must operate differently from classical networks and transfer quantum keys or information from one node to another. To address this challenge and deploy quantum networks, various solutions have been proposed which can be implemented in the short, medium and long term, based on technological advancement. These solutions, also known as different generations of quantum networks, are: First generation: quantum networks with trusted nodes Second generation: somewhat trusted quantum networks Third generation: untrusted quantum networks In first generation networks, quantum key distribution service is provided to users. In second generation networks, the idea of somewhat trusted nodes using multiple different paths to send a secure key is utilized. Third generation networks enable exchange of quantum information between quantum computers. Long-distance communications in these networks is achieved using quantum repeaters, which operate based on entanglement. Therefore, they are also referred to as quantum repeater networks, entanglement-based networks, or the quantum internet. In this webinar, the operating principles, applications, opportunities and challenges of each of these networks will be introduced.