Quantum Physics Breakthroughs: Observing Gold's Atomic Structure Under Extreme Pressure

Researchers at Lawrence Livermore National Laboratory conducted groundbreaking experiments observing gold's atomic structure under extreme pressure, achieving measurements at 10 million times Earth's atmospheric pressure. This study, published in Physical Review Letters, represents the highest-pressure structural measurement of gold ever made, shedding light on the behavior of materials in extreme conditions critical for planetary modeling and fusion science. Amy Coleman, a scientist at LLNL, emphasized the importance of understanding gold's behavior, stating, 'Knowing precisely how gold behaves ensures that every other experiment using it as a calibrant... is grounded in a robust and validated understanding of gold's behavior.'

Gold, due to its chemical stability and ease of detection with X-rays, serves as a reference material for high-pressure science, with its atomic structure under normal conditions arranged in a face-centered cubic structure. The findings indicated that this structure remains stable up to pressures approximately twice that of the Earth's core; however, beyond that point, a transition occurs where some gold atoms rearranged into a body-centered cubic structure. Coleman noted the significance of this coexistence between the structures, stating, 'These experiments extend structural measurements of gold into the terapascal regime and highlight the need for temperature diagnostics to refine phase boundaries.'

To achieve these extreme pressures, researchers utilized tailored laser pulses at the National Ignition Facility and the OMEGA EP Laser System at the University of Rochester. The experiments required ultra-precise timing, capturing atomic-scale X-ray diffraction snapshots in a billionth of a second. This method allowed scientists to obtain a definitive look at gold's crystal structure under such extreme conditions, resolving long-standing discrepancies between theoretical predictions and experimental observations.

Coleman further explained that these results provide a stronger foundation for using gold as a high-pressure standard and exploring matter under extreme conditions, which is crucial for understanding planetary interiors. The research not only advances our knowledge of material behavior under extreme conditions but also opens avenues for future studies in planetary science and material design, solidifying gold's role in high-pressure science applications.

In summary, the study marks a significant advancement in the field of high-pressure physics, potentially influencing various scientific domains, including the design of new materials and the understanding of phenomena occurring within planetary cores.