In the quantum world, molecular behavior often defies imagination. According to the Heisenberg uncertainty principle, observing a molecule is like watching a dance where position and velocity cannot be captured simultaneously. Yet this seemingly chaotic quantum dance actually follows a strict choreography. Even at absolute zero, molecules never cease moving due to zero-point energy, performing a silent atomic dance.

Recently, scientists from Goethe University Frankfurt and their collaborating institutions achieved the first direct measurement of this zero-point motion at the European X-ray Free-Electron Laser (XFEL) facility in Hamburg, Germany. They used the X-ray laser as a “spotlight” focused on individual molecules, capturing atomic snapshots to reveal the precise vibrational patterns of each atom. Professor Till Jahnke stated: “For the first time, we have directly measured this behavior in a single medium-sized molecule in its lowest energy state. This zero-point motion is a purely quantum mechanical phenomenon.” Medium-sized molecules, such as iodopyridine, possess 27 different vibrational modes, far more complex than simple molecules composed of just two or three atoms.

To capture images of these dancing particles, the scientists employed Coulomb explosion imaging. Ultra-short, high-intensity X-ray laser pulses trigger a controlled explosion of the molecule, generating high-resolution images. The COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) reaction microscope records the time and position of the fragment impacts, allowing reconstruction of the molecule’s original structure. Dr. Gregor Kastirke emphasized that this breakthrough result is the fruit of years of preparation and close teamwork. These findings not only provide entirely new insights into quantum phenomena but also demonstrate the enormous potential of the COLTRIMS reaction microscope. Professor Reinhard Dörner (likely the “Yangke” / “Jahnke” professor referred to) stated: “We are continuously improving the method, with the goal of eventually producing real short films of molecular processes.”