An atom passing through a hole in a dielectric membrane: Impact of dispersion forces on mask-based matter-wave lithography

TL;DR

This paper investigates how dispersion forces between atoms and dielectric membranes influence mask-based matter-wave lithography, revealing a significant reduction in effective hole size that impacts nanolithography precision.

Contribution

It provides a theoretical analysis of dispersion interactions affecting atom transmission through membranes, extending previous scalar wave models to include realistic atom-surface forces.

Findings

Effective hole radius is reduced by 1-7 nm for metastable helium.

Reduction is 0.5-3.5 nm for ground-state helium.

Thicker membranes and slower atoms increase the reduction.

Abstract

Fast, large area patterning of arbitrary structures down to the nanometre scale is of great interest for a range of applications including the semiconductor industry, quantum electronics, nanophotonics and others. It was recently proposed that nanometre-resolution mask lithography can be realised by sending metastable helium atoms through a binary holography mask consisting of a pattern of holes. However, these first calculations were done using a simple scalar wave approach, which did not consider the dispersion force interaction between the atoms and the mask material. To access the true potential of the idea, it is necessary to access how this interaction affects the atoms. Here we present a theoretical study of the dispersion force interaction between an atom and a dielectric membrane with a hole. We look at metastable and ground state helium, using experimentally realistic wavelengths (0.05-1 nm) and membrane thicknesses (5-50 nm). We find that the effective hole radius is reduced by around 1-7 nm for metastable helium and 0.5-3.5 nm for ground-state helium. As expected, the reduction is largest for thick membranes and slow atoms.