In a groundbreaking achievement, researchers at Northwestern University have successfully teleported a quantum state of light over more than 30 kilometers (approximately 18 miles) of fiber optic cable. Conducted amid significant internet traffic, this engineering feat marks a crucial advancement towards developing a quantum-connected computing network, enhancing encryption, and exploring new sensing methods.
Prem Kumar, a computing engineer leading the study, expressed enthusiasm about the breakthrough, stating, “This is incredibly exciting because nobody thought it was possible.” While this technology might not revolutionize daily commutes or expedite downloads, it demonstrates the potential for quantum states to traverse existing infrastructure, which could reshape future communications.
Revolutionizing Quantum Communications
The process of quantum teleportation resembles science fiction concepts, akin to the transport systems seen in Star Trek. It involves transferring the quantum possibilities of an object in one location to a similar object in another by destroying the original state. This procedure requires sending a single wave of information while ensuring that the quantum identity remains intact.
Quantum states resemble a “hazy smear of possibility,” vulnerable to decoherence from electromagnetic waves and thermal activity. Shielding these states within computers is challenging, but transmitting them through busy optical fibers filled with data transactions presents a new level of difficulty. The researchers faced the task of maintaining the integrity of a single photon against a staggering 400 gigabits per second of internet traffic.
To achieve this, the research team employed various techniques to limit the photon’s pathway and minimize scattering. “We carefully studied how light is scattered and placed our photons at a judicial point where that scattering mechanism is minimized,” Kumar explained. They discovered that quantum communication could occur without interference from classical channels that operate simultaneously.
Paving the Way for a Quantum Internet
While other research teams had previously demonstrated the transmission of quantum information alongside classical data in simulations, Kumar’s team stands out as the first to teleport a quantum state in a real-world internet environment. Each successful test contributes to the notion that a quantum internet is on the horizon, offering engineers new methods for measuring, monitoring, encrypting, and processing information without the need to overhaul existing internet infrastructure.
“Quantum teleportation has the ability to provide quantum connectivity securely between geographically distant nodes,” Kumar noted. He further emphasized that the development of specialized infrastructure for transmitting light particles may be unnecessary. By selecting appropriate wavelengths, classical and quantum communications can coexist within the same framework.
This research was published in the journal Optica, with an earlier version appearing in December 2024. The implications of this breakthrough extend far beyond theoretical physics, potentially transforming the landscape of global communication and security.
