Scientists perform first quantum teleportation over the Internet

The quantum state of light has been successfully transmitted over more than 30 kilometers of fiber optic cable filled with a huge flow of Internet traffic. Until recently, such an achievement was considered impossible, but researchers in the United States proved the opposite in 2024.

This is reported by ScienceAlert.

How quantum teleportation was realized

The ability to transmit quantum states over existing infrastructure is a significant step forward. It paves the way for a quantum-connected computing network, improved encryption, and new methods of detection and measurement.

The idea is to "transfer" the quantum capabilities of one object to another. This is done by deliberately measuring the original (and thus destroying its primary quantum state), which causes an identical state to emerge at a remote location.

Although such "teleportations" of quantum states occur instantaneously, they still require the transmission of a classical signal between the two points. The difficulty lies in the fact that an unstable quantum superposition quickly transitions to a normal state under the influence of the environment — any thermal or electromagnetic process can lead to decoherence.

While it is still possible to protect the quantum state inside a computer system, it is much more difficult to send individual photons over fiber optic lines with many gigabits of classical information (transactions, videos, messages). Accidental light scattering threatens the pristine quantum state, like cotton candy thrown into a river that quickly dissolves in water.

To preserve the "fragile" information of a photon in the face of 400 gigabits per second of traffic, the research team used a variety of techniques. They isolated the "channel" for the quantum signal, reduced the probability of scattering, and carefully separated the photon from other waves.

While other teams have modeled the compatibility of quantum channels with traditional virtual networks, this group's research is the first case of quantum teleportation of a real state of light coexisting with live Internet traffic.

Earlier, we wrote that scientists at the University of Oxford have taken a significant step towards the large-scale use of quantum computing by creating the first distributed quantum computer. 

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