Northwestern University engineers have made a groundbreaking discovery by successfully demonstrating quantum teleportation over a fiberoptic cable that is already carrying Internet traffic. This achievement opens up new possibilities for combining quantum communication with existing Internet infrastructure, making it much simpler to implement distributed quantum sensing or computing applications. The study, led by Northwestern’s Prem Kumar, a professor of electrical and computer engineering at the McCormick School of Engineering, will be published in the journal Optica. This development represents a significant advancement in the field of quantum communication and has the potential to revolutionize the way we think about classical and quantum networks.
Quantum teleportation, which is limited only by the speed of light, has the potential to make communication nearly instantaneous. This process relies on quantum entanglement, a phenomenon in which two particles are interconnected regardless of the distance between them. Instead of physically transmitting particles to convey information, entangled particles exchange information over large distances without the need for physical transportation. In optical communications, where all signals are converted to light, quantum communication uses single photons rather than millions of light particles used in classical communications. However, the challenge lies in ensuring that individual photons do not get lost in the sea of millions of light particles that make up regular Internet traffic.
To address this challenge, Kumar and his team devised a method to direct the delicate photons away from the congested traffic within the fiberoptic cables. By carefully studying how light scatters within these cables, the researchers identified a less crowded wavelength of light where they could place their photons. Additionally, they implemented special filters to reduce noise from conventional Internet traffic, allowing them to perform quantum communication without interference from the traditional channels. To test this new approach, the researchers set up a 30-kilometer fiberoptic cable with a photon at each end and successfully transmitted quantum information alongside regular Internet traffic. Despite the bustling activity within the cables, the quantum information was efficiently transmitted, demonstrating the feasibility of integrating quantum and classical communication within existing infrastructure.
Moving forward, Kumar and his team plan to expand their experiments over longer distances and aim to utilize two pairs of entangled photons to demonstrate entanglement swapping, a crucial step towards distributed quantum applications. They also plan to conduct experiments using real-world inground optical cables rather than experimental spools in the lab setting. Despite the challenges that lie ahead, Kumar remains optimistic about the potential of quantum teleportation to provide secure quantum connectivity between geographically distant nodes. By selecting appropriate wavelengths, existing infrastructure can be leveraged to support both classical and quantum communications, paving the way for a future where these two technologies can coexist harmoniously.
Overall, the successful demonstration of quantum teleportation over fiberoptic cables carrying Internet traffic represents a significant milestone in the field of quantum communication. This achievement has the potential to streamline the implementation of distributed quantum sensing and computing applications by leveraging existing infrastructure. The findings of this study could revolutionize the way we think about classical and quantum networks, offering a pathway towards next-generation communication systems that combine the speed and security of quantum communication with the robustness of classical infrastructure. With further research and development, the integration of quantum teleportation into existing fiber-optic networks could enable secure quantum connectivity over vast distances, opening up exciting possibilities for future technological advancements.