The quantum internet — a network that transmits information using the laws of quantum physics rather than conventional electronics — has moved a step closer to reality.
A team of researchers from four European universities has achieved a breakthrough that had never been done before: **quantum teleportation between two physically different quantum dots**, separated by a real-world optical link. The results were published in **Nature Communications** in early 2026.
**What Is Quantum Teleportation?**
First, a clarification: quantum teleportation doesn't involve moving matter. It's about transferring a **quantum state** — the exact configuration of a quantum system — from one location to another, without physically sending any particle between them.
What makes this powerful is that a quantum state can encode information in ways classical physics cannot: in superpositions (existing in multiple states simultaneously) and entanglements (correlations between particles that persist across any distance). Teleporting a quantum state means transferring that information perfectly, without copying it (which quantum mechanics forbids) and without sending it through a conventional channel (where it could be intercepted).
The challenge has always been doing this **reliably, between different physical systems, over real-world distances**.
**What the Team Achieved**
The experiment, led by scientists at **Sapienza University of Rome** with collaborators at **Paderborn University** (Germany), **Johannes Kepler University Linz** (Austria), and the **University of Würzburg** (Germany), used two semiconductor quantum dots — tiny nanoscale structures that emit individual photons — as the two ends of the teleportation link.
The key advance: previous quantum teleportation experiments typically used **identical** quantum emitters. This team used **two different quantum dots**, each fabricated separately, with slightly different physical properties. Bridging the differences between them is precisely what makes this experiment difficult — and precisely what makes it relevant to real-world quantum networks, which will inevitably involve connecting different types of hardware.
The two quantum dots were connected by a **270-metre free-space optical link**, and the team successfully teleported the polarisation state of a single photon from one dot to the other with a **fidelity of 82 ± 1%** — comfortably above the 66.7% classical limit (the best any non-quantum system could achieve by chance).
**Why This Matters**
A quantum internet needs **quantum relays** — intermediate nodes that receive a quantum signal, preserve its quantum properties, and pass it on to the next node. Without relays, quantum signals degrade over distance and can't be amplified conventionally (the quantum no-cloning theorem forbids it).
Quantum teleportation is how those relays work. And to build a real network, the relays need to operate between different physical systems — not just identical ones built in the same lab.
This experiment demonstrates that quantum teleportation between *different* quantum dot systems is achievable over a real physical link. The next step the team is targeting: **entanglement swapping** between two quantum dots — which would allow the creation of entanglement between particles that have never directly interacted. That would constitute the world's first true quantum relay.
**The Quantum Internet Timeline**
A full quantum internet is still years away. But each of these experimental milestones matters, because it proves the physical principle is sound — and that the engineering challenges, while real, are solvable.
For fields like cryptography (quantum keys that are theoretically unbreakable), distributed quantum computing, and ultra-precise scientific sensing, the quantum internet isn't a fantasy — it's an engineering project. And it just got a little closer. ⚛️
*Sources: Nature Communications (2026) · Paderborn University · SciTechDaily · Quantum Computing Report*
