Quantum light on tour - How single photons influence the future of communication
- Veranstaltungen
- Brötchen-und-Borussia

When we communicate online today, it is usually via light - light that is sent through fiber optic cables in the form of pulses. However, the smallest unit of light, the so-called single photon, plays by its own rules, namely those of quantum physics. This brings with it a few challenges, but also many exciting possibilities. Quantum communication is particularly advantageous in terms of security: messages that are transmitted using single photons can be made absolutely secure by the laws of physics.
To produce single photons, for example, you can operate a laser very weakly - but this is quite unreliable because the single photons come at random. That's why you need special sources, so-called quantum emitters.
In this lecture, I will explain how such quantum emitters work and how far the technology has come. We will also look at what we still need to build a real quantum internet. Finally, there will be an insight into the “QuanTour” project, in which a quantum emitter travels across Europe and promotes the International Quantum Year 2025.
![Band structure of 2D semimetal based on HgTe quantum well. Experimental points are obtained from the analysis of the cyclotron resonance in the quasi-classical approximation. Solid lines are predictions of the kp theory with no free parameters. Splitting of the conduction (e1,2) and valence (h1) band is due to the quantum confinement. [J. Gospodaric, AP, et al., PRB 104, 115307].](/storages/physik/_processed_/b/5/csm_Kolloquium_Pimenov_0fa7761647.png)





