Universal Matter-Wave Interferometry – From Macromolecules to Massive Nanoparticles

In 2026, quantum mechanics is celebrating a sequence of centenaries including Erwin Schrödinger’s wave equation and Born's rule for quantum measurement. And yet, the community is still debating the meaning of the quantum wave function, its implications for philosophy as well as technology.
I will discuss our long series of experiments at the University of Vienna where we have observed the quantum wave nature of fullerenes, polypeptides, tailored macromolecules, and metal nanoparticles containing several thousand atoms in a single delocalized body. All experiments confirm that it is possible to create quantum superpositions that contradict our classical worldview of well-defined trajectories. I will describe our current efforts to prepare even larger systems, both metal and dielectric nanoparticles with improved size control and much reduced kinetic energy, including recent experiments to cool the librational motion of trapped nanorotors into their 2D quantum ground state.
Such sources shall allow us to shift the limits of experimentally verified macroscopicity in quantum mechanics even further.