Quantum Object Photon
For Student Groups

Experiments

• Single photons at a beam splitter
• Coincidence and stochastic predictability
• Construction of a Mach-Zehnder interferometer
• Interference in experiments and simulations

Experiments on single quantum objects are challenging and enlightening. In this course, participants will investigate the quantum object photon in a series of experiments and simulations.

After an introduction to the generation and measurement of photons, the first experiment focuses on the behavior of single photons at a beam splitter. It is shown that even after passing through a beam splitter, single photons are only measured as a whole and thus exhibit quantum properties. The participants use coincidence methods for evaluation. Furthermore, the connection between the stochastic predictability of measurement results and quantum mechanical superposition is discussed.
In the second part of the course, participants build their own Mach-Zehnder interferometers to investigate interference effects and operate them with laser light. They examine the behavior of single photons in the Mach-Zehnder interferometer in corresponding simulations. The comparison of experiment and simulation and the interpretation of the results focus on complementarity, quantum mechanical states and their superposition as well as the concept of phase.

In the concluding outlook, interaction-free measurements, quantum mechanical entanglement and their technological use, for example in interception-proof data transmission and in quantum computers, are discussed.

Keywords

Quantum objects; coincidence measurements; photons in the interferometer; interpretation of quantum physics