Researchers have successfully used a pair of neighboring atomic columns in a silicon crystal as an atomic-scale double slit, directly reading thermal vibrations from created electron interference fringes. According to a study published in Nature by Koudai Tabata and colleagues, this nanoscale adaptation of Young’s double-slit experiment operates on a scale roughly ten million times smaller than the classical demonstration.
The Atomic-Scale Double-Slit Experiment
Thomas Young’s classical double-slit experiment, devised roughly two hundred years ago, uses light waves separated by about one millimeter to demonstrate wave interference. In the new study, researchers adapted this concept to the atomic scale using advanced scanning transmission electron microscopy (STEM). According to the research team, an ultra-sharp electron beam was scanned across a silicon crystal to record detailed diffraction patterns at precise probe positions.
The team extracted patterns formed when the electron probe passed exactly midway between two neighboring silicon atomic columns spaced just 136 picometers (pm) apart. This pair of atomic columns functioned as a double slit, producing distinct interference fringes. These fringes only survive when neighboring atoms vibrate in step with one another, enabling the team to measure how closely the thermal vibrations of the two atoms are correlated.
Bond Stiffness and Thermal Conduction
Analyzing the interference fringes revealed that the atomic vibration correlation was stronger along the atomic bond than across it. According to the research findings, this correlation barely changed even at temperatures up to 900 Kelvin. This stability indicates that the measured quantity directly reflects the stiffness of the bond itself.
Because heat travels through semiconductors as atomic vibrations, this bond stiffness dictates how readily heat passes from one atom to the next. The research team notes that this experimental method provides a direct way to observe, bond by bond, where heat flows easily and where it stalls. This capability marks a step forward for the thermal design of future semiconductor devices.
Research Team and Methodology
The study, titled “Atomic-scale double-slit interferometry with a focused electron probe,” was conducted by Koudai Tabata, Takehito Seki, Toma Susi, Ryo Ishikawa, and Naoya Shibata. By combining high-resolution STEM imaging with precise diffraction pattern analysis, the team bypassed previous limitations in observing atomic-level dynamics within crystal lattices. The resulting data bridges the gap between macroscopic thermal properties and microscopic atomic behavior.
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