Physicists have successfully captured the real-time break-up of C60 fullerenes, also known as Buckminsterfullerenes, using advanced X-ray imaging techniques. This significant achievement was accomplished through the collaboration of researchers from several prestigious institutions, including the Max Planck Institute for Nuclear Physics in Heidelberg, the Max Planck Institute for the Physics of Complex Systems in Dresden, and the Max Born Institute in Berlin. The findings were published in the journal Science Advances on November 21, 2025.
The study utilized ultrashort and intense X-ray pulses from accelerator-based free electron lasers (FELs) at the Linac Coherent Light Source (LCLS) located at the SLAC National Accelerator Laboratory. This innovative approach allows scientists to directly observe the dynamic reshaping of molecules under the influence of strong laser fields. The ability to visualize these processes in real-time is crucial for advancing our understanding of complex many-body dynamics in laser-driven polyatomic molecules.
Researchers focused on C60, a molecule characterized by its spherical shape, and analyzed its response to varying intensities of infrared (IR) laser pulses. The study yielded two primary parameters from the X-ray diffraction patterns: the average radius (R) of the molecule and the Guinier amplitude (A), which measures the strength of the X-ray scattering signal. The Guinier amplitude is directly proportional to the squared number of atoms in the molecule that act as scattering centers.
The experimental results demonstrated distinct molecular behaviors across different laser intensity regimes. At low intensity (1 × 1014 W/cm2), the C60 molecule initially expands before exhibiting minor fragmentation, as indicated by a gradual decline in the Guinier amplitude. As the intensity increased to an intermediate level (2 × 1014 W/cm2), the molecule’s expansion was followed by a notable decrease in its radius and a corresponding drop in the Guinier amplitude, suggesting significant fragmentation.
At the highest intensity tested (8 × 1014 W/cm2), the results revealed rapid expansion and a simultaneous decrease in the Guinier amplitude. This phenomenon occurred at the leading edge of the laser pulse, resulting in the removal of nearly all outer valence electrons. The team noted that while their model calculations aligned with some experimental observations, discrepancies remained, particularly regarding the predicted oscillatory behavior of the radius and amplitude caused by molecular “breathing.”
To achieve better alignment between experimental data and theoretical predictions, the researchers introduced an ultrafast heating mechanism affecting atomic positions within the molecule. The study highlights that multi-electron dynamics driven by intense laser fields continue to represent a challenge in theoretical modeling, as a comprehensive quantum mechanical treatment is currently unattainable.
These X-ray imaging techniques provide an ideal platform for investigating fundamental quantum processes in increasingly complex molecular systems. The insights gained from this research could pave the way for future advancements in controlling chemical reactions through laser fields, ultimately enhancing our understanding of molecular dynamics.
For more detailed information, refer to the article by Kirsten Schnorr et al in Science Advances (DOI: 10.1126/sciadv.adz1900).
