Moderator and science journalist Jacob Beautemps delves into the world of the quantum internet. Projects like those of our T-Labs – including their test track in Berlin – are already putting theory into practice. What is already possible today and how the quantum internet works – this is what a new episode of “Breaking Lab”, a popular knowledge format on YouTube, is about.
In the classic Internet, information is transmitted as bits – i.e. as 0 or 1. The quantum Internet involves “qubits”. They can be 0, 1 or both at the same time. This superposition is called “superposition”.
There is also a second special feature, the so-called entanglement. Two particles are linked together in such a way that their state is related – even over large distances. If you measure one, you know the condition of the other. These quantum effects form the physical basis for the quantum internet and its applications.
At its core, the quantum internet is a network of quantum devices such as quantum computers or quantum sensors that exchange such qubits. Research speaks of six stages of development of the quantum internet: from the first, point connections to a global network of quantum computers in stage 6. Today we are at the beginning, i.e. on the first stage.
Tap-proof communication through physics
One of the most exciting applications is tap-proof communication. Today, encryption is mostly based on complex mathematical problems. Procedures like RSA Although they make it very difficult for attackers to calculate keys, powerful quantum computers could crack such methods much more quickly in the future.
The quantum internet starts at a different point. The actual data remains classically encrypted, but the key is transmitted via qubits. The highlight: quantum states cannot be copied without loss. If an attacker tries to read the state of a qubit, he will inevitably change it. This interference can be detected on the receiving side, especially when entangled particles are involved.
This creates a communication network in which attempts to eavesdrop do not go unnoticed.
Distributed quantum computing: Many quantum computers instead of one
Quantum computers are still in their early stages. Today, systems work with around a hundred qubits. However, for many complex applications, much more would be needed. However, the larger the systems become, the more difficult it becomes to operate them stably and with few errors.
This is where the idea of distributed comes in Quantum computing an: Instead of building a huge quantum computer, several smaller systems are connected via the quantum internet. Qubits can be exchanged between them, and algorithms run in parallel on several computers. In the end, a virtual “mainframe” computer is created.
The quantum internet provides the infrastructure for this, similar to today’s distributed internet Cloud computingbased only on qubits.
Quantum Sensing: Measuring in a Network
Another application is quantum sensing. It’s about carrying out extremely precise measurements – for research, medicine or geophysics, for example.
In classic sensor networks, each sensor measures itself. The data is later compiled centrally, averaged and evaluated. In a quantum network, however, sensors can be coupled via entangled qubits. Several quantum sensors then record a measured value together.
A quantum internet makes it possible to connect such distributed quantum sensors – for example telescopes in distant locations for particularly precise observations of the sky.
Berlin as a test field – quantum and classic internet in the same cable
As a Quantum Internet via real fiber optic networks The T-Labs at Deutsche Telekom are testing in the “Berlin Quantum Fiber Testbed”. In this experimental network, classical data signals and quantum signals run through the same optical fiber.
The challenge: The signals must not interfere with each other. Glass fibers transmit light in different wavelength ranges, called bands. For the experiment, the classic data traffic remained in the usual C band and was therefore far enough away to minimize interference, but still technically usable.
Together with the US company Qunnect, the researchers achieved a record. They were able to distribute entangled photons over 30 kilometers of fiber optics with 99 percent accuracy (fidelity) – and this was stable for 17 days in continuous operation. In initial tests over around 100 kilometers, around 90 percent accuracy remains. That’s enough for shorter distances, such as within a city.
For comparison: In classic optical networks, amplifier stations are now located at intervals of around 80 kilometers. Significantly shorter distances are currently required for quantum connections – approximately one node every 30 kilometers.
The bottleneck: quantum repeaters and timetable until 2050
In order for the quantum internet to work over long distances, it needs special nodes – so-called quantum repeaters. You can create entanglement yourself and divide long distances into several shorter sections.
Such quantum repeaters are considered extremely complex. Studies, for example by Fraunhofer ISI, assume that commercial solutions cannot be expected until around 2035 at the earliest. Experts estimate that it will take another 15 to 20 years for the quantum internet to be developed on a large scale.
The T-Labs see their task as preparing today’s network for these technologies in good time: testing quantum components, integrating them into existing networks and evaluating how realistic a later migration is.
The quantum internet will not replace the classic internet. It complements it where special properties are required.
The video gives insights into technology that you don’t normally see because it’s in data centers. It also shows how practical AI assistants – such as those on the AI phone – are revolutionizing our everyday lives. It’s worth taking a look.
About the moderatorJacob Beautemps is a well-known science journalist and influencer in German-speaking countries. With his YouTube channel “Breaking Lab” he inspires a wide audience with technology and science topics, which he explains in a clear, well-founded and entertaining way. His goal: to make complex connections understandable.
