Abstract
Matter–wave interferometry has been used extensively over the last few years to demonstrate the quantum-mechanical wave nature of increasingly larger and more massive particles. We have recently suggested the use of the historical Poisson spot setup to test the diffraction properties of larger objects. In this paper, we present the results of a classical particle van der Waals (vdW) force model for a Poisson spot experimental setup and compare these to Fresnel diffraction calculations with a vdW phase term. We include the effect of disc-edge roughness in both models. Calculations are performed with D2 and with C70 using realistic parameters. We find that the sensitivity of the on-axis interference/focus spot to disc-edge roughness is very different in the two cases. We conclude that by measuring the intensity on the optical axis as a function of disc-edge roughness, it can be determined whether the objects behave as de Broglie waves or classical particles. The scaling of the Poisson spot experiment to larger molecular masses is, however, not as favorable as in the case of near-field light-grating-based interferometers. Instead, we discuss the possibility of studying the Casimir–Polder potential using the Poisson spot setup.
Highlights
VdW potential that is experienced by polarizable particles
We present the results of a classical particle van der Waals force model for a Poisson spot experimental setup and compare these to Fresnel diffraction calculations with a vdW phase term
In 1932, Lennard–Jones predicted that the vdW interaction of neutral atoms and molecules with solid surfaces is governed by a potential of the form
Summary
To justify the statement above, we compare a Fresnel diffraction model, which we have adapted to include a vdW phase term, to a simple classical deflection model. We use the same setup and parameters as in our experiment in [11]. The strength of the vdW interaction between deuterium and SiN was determined in a grid diffraction experiment by Grisenti et al [18], where they determined C3 = 0.33 ± 0.09 meV nm. We assume a smaller disc radius of R = 5 μm with a disc edge roughness of 30 nm and a disc thickness of d = 50 nm. It is reasonable to assume that a freestanding disc with such parameters can be fabricated using modern electron-beam lithography processing. We have recently demonstrated [22] that free-standing zone plates with a diameter of 388 μm and a thickness of about 150 nm can be produced successfully using electron-beam lithography and a silicon nitride membrane
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
