Atom Diffraction Achieves Sub-Nanometre Hole Transmission

The challenge of manipulating individual atoms presents exciting opportunities in fields like atom interferometry and atomic holography, but requires overcoming fundamental limitations in how atoms interact with materials. Eivind Kristen Osestad, Ekaterina Zossimova, Michael Walter, and Johannes Fiedler investigate the diffraction of helium atoms through incredibly small holes, just fractions of a nanometre wide, in atomically thin hexagonal boron nitride. Their work demonstrates that quantum mechanical calculations accurately predict significantly higher transmission rates than traditional, simplified models, suggesting the possibility of creating diffractive masks with far smaller features than previously thought. These findings are important because they reveal the limitations of commonly used approximations and highlight the need for quantum mechanical modelling when designing nanoscale devices for atom manipulation, even at relatively high atom velocities.

Atomic Diffraction Through Hexagonal Boron Nitride Nanoholes

This research details a theoretical and computational study of atomic diffraction through nanoscale holes in hexagonal boron nitride (hBN). The goal is to explore the feasibility of using hBN membranes with nanoholes as masks for matter-wave lithography, a technique aiming to create nanoscale structures using atomic beams. Researchers employed sophisticated calculations to determine the interaction between helium atoms and the hBN membrane, providing an accurate description of the forces acting on the atoms. They then simulated the propagation of helium atoms through the nanoholes by solving the time-dependent Schrödinger equation, allowing them to predict the resulting diffraction patterns and transmission probabilities.

Helium Diffraction Through Atomically Thin Membranes

This research demonstrates a pathway to significantly enhance atomic matter-wave diffraction through atomically thin hexagonal boron nitride membranes. Scientists performed numerical simulations, solving the time-dependent Schrödinger equation, to model helium atom propagation through sub-nanometre holes. These simulations reveal transmission rates substantially higher than those predicted by commonly used semi-classical approaches, suggesting the feasibility of designing diffractive masks with significantly smaller holes, provided fabrication techniques can achieve the necessary atomic-level precision. The study focused on modelling coherent diffraction of helium atoms through three distinct hole geometries, circular holes with diameters of 6 Å and 10 Å, and a snowflake-shaped hole, all within a representative section of the hBN material. Researchers observed notable differences in diffraction patterns even at atom velocities where semi-classical and quantum computational models were expected to converge, highlighting the importance of a fully quantum mechanical treatment.

Quantum Diffraction Reveals Enhanced Helium Transmission

This research presents a new quantum mechanical method for modelling the diffraction of helium atoms through sub-nanometre holes in hexagonal boron nitride membranes, challenging conventional semi-classical approaches. The results demonstrate significantly higher transmission rates than previously predicted, suggesting that much smaller holes can be used in atom interferometry and atomic holography than currently thought. The simulations reveal that the effective area for atomic diffraction is larger, particularly at lower velocities, and that the shape of the holes can be optimised to enhance transmission. These findings have important implications for technologies reliant on atomic-scale manipulation and sensing. By accurately modelling the quantum behaviour of atoms near the membrane, including the effects of attractive forces, this work highlights the importance of a quantum treatment even at relatively high velocities. Further research will investigate the effects of varying atom velocities, explore different materials like graphene, and analyse diffraction at larger angles.