Heavy atom quantum diffraction by scattering from surfaces

TL;DR

This paper demonstrates through quantum simulations that heavy particles can exhibit quantum diffraction when scattering from surfaces, challenging classical expectations and enabling surface quantum state verification.

Contribution

It reveals that heavy atom diffraction occurs in surface scattering due to quantum effects, even with large masses and classical conditions.

Findings

Quantum diffraction persists across various energies and angles.

Heavy particles can produce observable interference patterns.

The effect can verify quantum surface properties at low temperatures.

Abstract

Typically one expects that when a heavy particle collides with a surface, the scattered angular distribution will follow classical mechanics. The heavy mass assures that the de Broglie wavelength of the incident particle in the direction of the propagation of the particle (the parallel direction) will be much shorter than the characteristic lattice length of the surface, thus leading to a classical description. Recent work on molecular interferometry has shown that by increasing the perpendicular coherence length, one may observe interference of very heavy species passing through a grating. Here we show, using quantum mechanical simulations, that the same effect will lead to quantum diffraction of heavy particles colliding with a surface. We find that the effect is robust with respect to the incident energy, the angle of incidence and the mass of the particle. It may also be used to verify the quantum nature of the surface and its fluctuations at very low temperatures.