Researchers Capture Atomic Twists of Light in Groundbreaking Study

A collaboration between researchers at Cornell University and Stanford University has achieved a significant breakthrough in observing atomic movements triggered by light. Using ultrafast electron diffraction, the team captured the twisting motion of atomically thin materials in a process that occurs in just a trillionth of a second. This pioneering work, published on November 12, 2025 in the journal Nature, reveals new insights into how light can be used to manipulate materials, potentially leading to advancements in superconductivity, magnetism, and quantum electronics.

At the heart of this study is the ability to observe atomic layers in a crystalline structure responding in real time to precisely timed bursts of energy. The researchers found that these layers do not merely remain static once stacked at a fixed angle. Instead, they twist and untwist dynamically, akin to dancers synchronizing their movements to a rhythm. The findings challenge previous assumptions about the rigidity of moiré materials and highlight the fluidity of atomic arrangements under light exposure.

Jared Maxson, a professor of physics at Cornell and co-corresponding author of the paper, explained the significance of the research. “By stacking and twisting these atomically thin layers, you can significantly alter how a material behaves. We’ve shown that we can enhance that twist dynamically with light, and we can actually see it happening,” he stated.

The experimental setup relied on a specialized ultrafast electron diffraction instrument developed in Maxson’s lab. This sophisticated equipment fires intense bursts of electrons at a sample immediately after it has been struck by a laser pulse. This pump-and-probe technique allows researchers to track atomic shifts over time, revealing intricate details of the material’s response.

A crucial component of the experiment was the Electron Microscope Pixel Array Detector (EMPAD), also developed at Cornell. Originally intended for capturing still images, the EMPAD was adapted to function as a sensitive movie camera, enabling the team to capture subtle atomic movements that could have otherwise been obscured. “Most detectors would have blurred out the signal,” Maxson remarked. “The EMPAD let us capture incredibly subtle features.”

The materials used in this groundbreaking research were engineered by Fang Liu, project lead at Stanford, who noted the collaborative effort was essential for success. “There’s no way we could have witnessed this phenomenon without combining materials understanding with electron-beam expertise,” Liu said. “This was a true collaboration.”

The analysis of the data was significantly enhanced by contributions from Cameron Duncan, a doctoral student in Maxson’s group, who played a pivotal role in reconstructing atomic motion from complex diffraction patterns. “We were the first to succeed in finding the ultrafast moiré signal because we customized our home-built hardware specifically to enhance its diffraction-resolving power,” Duncan explained.

Looking ahead, Liu’s lab has already created new moiré samples designed to extend the capabilities of Cornell’s ultrafast instrument. The teams plan to conduct further experiments to explore how different materials and twist angles respond to light, which could deepen their understanding of real-time control over quantum behavior.

This research marks a significant advancement in the field of atomic physics and materials science, paving the way for innovative technologies that leverage light to manipulate material properties at the atomic level. The collaboration between Cornell and Stanford exemplifies the power of interdisciplinary teamwork in addressing complex scientific questions.