Researchers at the University of Pennsylvania have demonstrated the transmission of quantum signals over existing commercial fiber-optic cables using standard Internet Protocols, marking a significant step toward practical quantum networking.

Their tests on Verizon's campus fiber network showed that fragile quantum signals can coexist with classical internet traffic on current infrastructure, paving the way for integrating quantum communication into everyday networks.

This breakthrough involved transmitting quantum information through classical internet protocols, routers, and fiber optic cables, suggesting that future quantum internet could leverage existing network technology to accelerate development.

Quantum internet promises secure communication and the networking of quantum computers, enabling complex computations and data exchange, but faces challenges such as the fragility of quantum states and incompatibility with traditional network components.

The research lays a foundation for more advanced hybrid networks with higher data rates and scalability by utilizing existing infrastructure for quantum applications, moving closer to practical deployment.

Experts note that future quantum internet protocols will resemble classical ones but will require dedicated infrastructure due to quantum-specific limitations like the inability to use signal amplifiers.

The study utilized quantum entanglement to enable linked particles to affect each other instantaneously, which can facilitate secure data transfer and distributed quantum computing.

A silicon-based 'Q-chip' was developed to coordinate classical and quantum signals, allowing quantum data to be measured without destruction and integrated into existing network protocols.

Current limitations include the inability to amplify quantum signals over long distances without destroying entanglement, but the research demonstrates early progress by routing quantum signals over existing fiber.

Overcoming the challenge of maintaining quantum fidelity during transmission, an error correction method was developed that uses classical signals to infer quantum corrections, achieving over 97% fidelity in real-world conditions.

The silicon 'Q-chip' can be mass-produced, making it feasible to expand quantum networks by connecting more chips and nodes to existing fiber infrastructure.

This approach integrates quantum information into current internet infrastructure, indicating potential for scalable quantum networks that could revolutionize secure communication and computing.

While quantum networks currently support secure transfer over distances up to 100 kilometers, connecting quantum computers for cloud computing remains a key future goal.