Scientists have successfully captured the real-time break-up of C60 fullerenes, commonly known as “Buckminsterfullerenes,” using advanced X-ray imaging techniques. This groundbreaking research, conducted by physicists from the Max Planck Institutes in Germany, marks a significant advancement in understanding the dynamics of polyatomic molecules under intense laser fields.
The study involved collaboration between 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, alongside institutions from Switzerland, the United States, and Japan. The findings were published on November 21, 2025, in the journal Science Advances.
Advancements in Laser-Molecule Dynamics
The research utilized ultrashort and intense X-ray pulses from accelerator-based free electron lasers (FELs) to observe the reshaping of molecules directly. The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory served as the experimental platform. This innovative approach allowed researchers to analyze how C60 responds to strong infrared (IR) laser pulses in real-time.
By examining the X-ray diffraction patterns during the molecule’s response, key parameters were extracted, including the average radius (R) of the C60 molecule and the Guinier amplitude (A). The Guinier amplitude serves as a measure of the strength of the X-ray scattering signal and is proportional to the squared number of atoms in the molecule acting as scattering centers. Changes in R indicate the expansion or deformation of the molecule, while A provides insights into the fragmentation mode and the size distribution of fragments.
Insights from Experimentation
The experimental results revealed distinct behaviors across different laser intensity regimes. At low laser intensity (1×1014 W/cm2), the C60 molecule initially expanded before fragmenting, as indicated by the gradual decrease in the Guinier amplitude. As intensity increased to (2×1014 W/cm2) and then to (8×1014 W/cm2), the molecule exhibited rapid expansion and significant fragmentation.
Notably, the researchers observed that at the highest intensity, the laser pulse’s leading edge caused rapid removal of nearly all outer valence electrons. The model calculations conducted at the MPI-PKS demonstrated a theoretical understanding of these dynamics, although some discrepancies with experimental data were noted. Specifically, the model predicted an oscillatory behavior in both R and A, which was not observed in the actual measurements.
To reconcile these differences, the research team introduced an ultrafast heating mechanism affecting atomic positions within the molecule. This adjustment yielded better agreement between the model and experimental results, emphasizing the need for further investigation to enhance understanding of intense-laser interactions with matter.
Ultimately, this research highlights the complexities of multi-electron dynamics under intense laser fields and the challenges that remain in achieving a full quantum mechanical description. The X-ray imaging of C60 provides an ideal platform for exploring fundamental quantum processes in increasingly complex molecular systems, paving the way for advancements in controlling chemical reactions with laser fields.
For more details, refer to the original study: Kirsten Schnorr et al., “Visualizing the strong-field induced molecular break-up of C60 via X-ray diffraction,” published in Science Advances (2025). DOI: 10.1126/sciadv.adz1900.
