Gold’s hidden side: Scientists discover needle-shaped quantum clusters

Scientists at the University of Tokyo have discovered a novel form of gold nanoclusters—needle-shaped structures they call "gold quantum needles"—by capturing gold clusters at their earliest growth stages. Unlike typical gold nanoclusters that form roughly spherical shapes, these quantum needles grow unevenly, elongating through repeating units of three and four gold atoms. This unique atomic arrangement leads to quantum behavior, where electrons occupy fixed energy states. The discovery was made possible by deliberately slowing the growth process and analyzing the clusters with single-crystal X-ray diffraction, revealing unprecedented insight into the initial formation of gold nanoclusters, a process previously considered a "black box." The gold quantum needles exhibit strong interactions with near-infrared light, suggesting potential applications in biomedical imaging and energy conversion technologies. By understanding the stepwise growth of these clusters, researchers hope to develop methods to precisely control the shape and properties of nanoclusters, moving beyond the current unpredictability of their synthesis. While practical production and modification of these quantum