In a groundbreaking achievement, researchers have successfully teleported a quantum state of light over a distance exceeding 30 kilometers (approximately 18 miles) using fiber optic cables while navigating through heavy internet traffic. This remarkable feat, accomplished in 2024, challenges previous notions about the feasibility of such technology.
The team, led by Prem Kumar, a computing engineer from Northwestern University, emphasized the significance of this demonstration. “This is incredibly exciting because nobody thought it was possible,” Kumar stated. Although this advancement does not imply that individuals will soon be able to teleport to work or download media at lightning speeds, it marks a pivotal step toward the establishment of a quantum-connected computing network, improved encryption methods, and innovative sensing technologies.
Teleportation, which bears a resemblance to the fictional transport systems in “Star Trek,” involves transferring the quantum possibilities of an object from one location to another. This process requires the careful destruction of the original object while imposing its quantum characteristics onto a similar object at a different location. Despite the instantaneous nature of entanglement that connects the two objects, the teleportation process relies on transmitting a wave of information across distances.
The preservation of quantum states is particularly challenging when transmitting a single photon through optical fibers that also carry vast amounts of classical data. The researchers faced the daunting task of protecting the delicate quantum state of a photon amid a 400 gigabit-per-second flow of internet traffic. To achieve this, they employed various techniques to confine the photon”s channel, thereby minimizing scattering and interaction with other data streams.
“We carefully studied how light is scattered and positioned our photons at a location where that scattering mechanism is minimized,” Kumar explained. “We discovered that we could conduct quantum communication without interference from the classical channels that operate simultaneously.”
While other research teams have previously managed to transmit quantum information alongside classical data in simulations, Kumar”s group stands out as the first to teleport a quantum state alongside actual internet traffic. Each successful test reinforces the notion that a quantum internet is on the horizon, providing computing engineers with unprecedented tools for monitoring, measuring, encrypting, and processing information without requiring a complete overhaul of current internet infrastructure.
“Quantum teleportation has the potential to enable secure quantum connectivity between nodes located far apart,” Kumar noted. He pointed out that many had assumed specialized infrastructure would be necessary for sending particles of light. “By selecting the proper wavelengths, we eliminate the need for new infrastructure. Classical and quantum communications can coexist,” he added.
This important research has been published in Optica. An earlier version of this article was released in December 2024.
