Testing the upper edge of the quantum realm

In the 1920s and 1930s, Louis de Broglie established his ground-breaking idea that matter, like light, has particle-wave duality. Today, scientists are following in his footsteps to see if such quantum superpositions can be demonstrated with larger molecules to probe where the quantum and classical realms collide.

Kiałka et al. provide a guide to such quantum experimentation with macromolecules by combining advances in macromolecule interferometry with cluster physics. The authors hope this technique can be used to demonstrate wave-particle duality for a wide array of materials with orders of magnitude higher mass and width of quantum delocalization than have yet been shown.

“It is extremely intriguing to ask, ‘If quantum physics is correct, why do we then experience a classical world?’” said author Markus Arndt. “No one knows if quantum physics is all there is, or if we need to modify it in regimes that have not been tested so far. This is why we are developing these new experiments.”

Such experiments could help set new bounds on quantum mechanics independently of models. They could also initiate new tests of modifications to quantum mechanics and gravity with composite quantum systems, and in searches for light dark matter.

Currently, the authors are testing magnetron sputtering and deep UV light sources to create and detect large clusters that can be used for such experiments. Preliminary results are promising, and the authors hope these nanoparticles could push the mass record, with a goal of doubling the record annually and diversifying the material classes to metal and silicon clusters.

Source: “A roadmap for universal high-mass matter-wave interferometry,” by Filip Kiałka, Yaakov Y. Fein, Sebastian Pedalino, Stefan Gerlich, and Markus Arndt, AVS Quantum Science (2022). The article can be accessed at https://doi.org/10.1116/5.0080940 .