Atomic diffraction through a nanograting

We offer an M2 internship and a PhD thesis for 2025 ! See here !

1) Group members:

Permanent: Gabriel Dutier (Pr.), Quentin Bouton (CR CNRS), Nathalie Fabre (MCF), Francisco Perales (MCF), Martial Ducloy (DRCE Emeritus).
PhD students: Julien Lecoffre, Ayoub Hadi et Matthieu Bruneau (cotutelle avec l’Université de Leibniz à Hanovre en Allemagne)

Contacts : Gabriel Dutier, Quentin Bouton, Nathalie Fabre.

2) Research context:

An atom in front of a surface is one of the simplest and fundamental problem in physics. Yet, it allows testing quantum electrodynamics, while providing platforms for the nanotechnologies and quantum technologies. In particular, the presence of electromagnetic quantum fluctuations (associated to the zero-point energy in quantum mechanics) leads to a force between an atom and a surface (macroscopic body). This force is called the Casimir-Polder (C-P) force.

Every polarizable object in nature is subjected to the C.P force. This force prevails at the nanoscopic scale, entailing its strong connections with many domains, from nanotechnology to physical chemistry. The basic understanding of this force is crucial for probing novel physics involving an atom and a material at a small relative distance.

In this context, we have built slow atomic beam interacting with a nanograting (grating featuring nanoscale dimensions such as 100 nm width slits, 200 nm period and 100 nm thickness for instance). The nanogratings are developed and manufactured by the team itself within the RENATECH framework at “Institut d’Electronique de Microelectronique et de Nanotechnologie” (IEMN, Lille). Passing through the nanograting, the atoms interact with the slits within the C-P interaction for atom-surface distance up to some dozen nm.

3) Experiment:

Our unique experimental set-up uses a laser-cooled Argon source in the 43P2 metastable state to create a slow atomic beam with velocity ranging from 10 m/s and 50 m/s [1]. The atoms in the beam interact with the nanograting within the C-P force. The metastable Argon atoms are then detected with an efficient time-position detection at the single atom level with microchannel plates (Figure 1). The atomic wave packet phase shift induced by the atom-surface interaction modifies the interference pattern. The diffraction spectrum is here dominated by the C.P interaction due to the large interaction time allowed by the slow velocities (the phase being proportional to the interaction time in the nanograting). It leads to a highly sensitive measurements of the C.P force (see Figure 2).

Figure 1: Sketch of the experiment. Neutral Argon atoms interact with a nanograting within the C-P potential. This interaction with the nanograting leads to a diffraction pattern. Information related to the C-P potential are extracted from the analysis of the interference pattern.

Figure 2: Experimental diffraction spectrum of metastable argon through a nanograting at 19 m/s (in blue). The angle θ is the diffraction angle. In red, theoretical curve without considering the C-P interaction. The difference between the blue and red curve underlines how strongly the diffraction spectrum is dominated by the C-P interaction.

Figure 3: This video shows single Argon atoms arriving on the microchannel plates detector during an experimental acquisition. As more and more atoms reach the detector, the full interference pattern becomes more and more visible!

4) Group picture:

5) Intership/PhD proposal:

We are always looking for prospective PhD students, postdocs or interns to join our group. Do not hesitate to contact one of the staff members. We are looking forward to hearing from you!

This year, we offer an M2 internship! See here.

6) Recent news:

July 2024: we publish a new preprint where we present a method utilizing atomic diffraction patterns and statistical analysis tools to infer the Casimir-Polder interaction between Argon atoms and a silicon nitride nanograting. Read our new preprint if you are interested: arXiv:2407.14077 (2024).

July 2024: we have been awarded an ANR funding on the Ar experiment setup.

March 2024: Julien Lecoffre participates at the regional final of “Ma thèse en 180 secondes”! His video can be found here.

May 2023: our paper «Quantum description of atomic diffraction by material nanostructures» is now published in Phys. Rev. Research. Many thanks to our theory collaborator N. Gaaloul and E. Charron.

December 2023: check our new paper posted on arXiv (arXiv:2312.12818) where we present a theoretical model of matter-wave diffraction through a material nanostructure.

October 2023: we welcome Ayoub Hadi, new PhD student on the experiment! Welcome Ayoub!

October 2023: we welcome Matthieu Bruneau, new PhD student in co-tutelle between our team and the University of Leibniz in Hanover in Germany. Welcome Matthieu!

7 ) Publications:

2024

J. Lecoffre, A. Hadi, M. Bruneau, C. Garcion, N. Fabre, E. Charron, N. Gaaloul, G. Dutier, Q. Bouton, Measurement of Casimir-Polder interaction for slow atoms through a material grating, arXiv:2407.14077 (2024).
C. Garcion, Q. Bouton, J. Lecoffre, N. Fabre, É. Charron, G. Dutier, and N. Gaaloul, Quantum description of atomic diffraction by material nanostructures, Phys. Rev. Research 6, 023165 (2024).

2021

C. Garcion, N. Fabre, H. Bricha, F. Perales, S. Scheel, M. Ducloy, and G. Dutier, Intermediate-Range Casimir-Polder Interaction Probed by High-Order Slow Atom Diffraction, Phys. Rev. Lett. 127, 170402 (2021).

8) Collaborations:

Institut d’Electronique de Microelectronique et de Nanotechnologie (Lille, France).
N. Gaaloul (University of Leibniz in Hanover, Germany).
E. Charron (University Paris-Saclay, Institut des Sciences Moléculaires d’Orsay, France).
Kanu Sinha (Arizona State University).

9) Funding:

10) Former members:

– Charles Garcion (Thèse 2019-2022)
– Ilias Boutaleb (2023, M1, Sorbonne université)
– Hajra Ghulam (2022, M1, Université de Paris)
– Fabio D’ORTOLI-GALERNEAU (2022, L3, ENS)
– Baazia Elmehdi (2022, Ingénierie en Instrumentation, Institut Sup Gallilée)
– Hanane Bricha Tazi (thèse 2016-2019)
– Franck Correia (thèse 2015-2018)
– Mehdi Hamamda (2012-2015)
– Thierry Taillandier-Loize (thèse 2011-2014)

11) References:

[1] C. Garcion, N. Fabre, H. Bricha, F. Perales, S. Scheel, M. Ducloy, and G. Dutier, Intermediate-Range Casimir-Polder Interaction Probed by High-Order Slow Atom Diffraction, Phys. Rev. Lett. 127, 170402 (2021).

[2] J. Lecoffre, A. Hadi, M. Bruneau, C. Garcion, N. Fabre, E. Charron, N. Gaaloul, G. Dutier, Q. Bouton, Measurement of Casimir-Polder interaction for slow atoms through a material grating, arXiv:2407.14077 (2024).

[3] R. Bennett, Revealing short-range non-Newtonian gravity through Casimir–Polder shielding, New J. Phys. 21 033032 (2019).

Interferometry and optics for atoms (OIA)