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Nous présentons une méthodologie de conception, basée sur une modélisation exacte de la diffraction par des réseaux, qui vise à concevoir des réseaux de diffraction qui satisfont aux exigences du piégeage atomique tout en tenant compte des contraintes et des tolérances de fabrication. Nos résultats montrent que des réseaux pertinents peuvent être facilement conçus à l'aide de cette méthode, et nous identifions des conceptions avec des tolérances de fabrication accrues et une meilleure résistance à l'imprécision, ce qui simplifie et augmente les chances de réaliser des pièges atomiques magnéto-optiques à réseaux (GMOTs) efficaces.

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We present a design strategy for grating magneto-optical traps (GMOTs). It takes the three most relevant optical properties for laser cooling (radiation pressure balance, specular reflection cancellation, and diffracted polarization) to build a scalar figure of merit. We use a rigorous coupled wave analysis (RCWA) simulation to find a geometry that maximizes this figure of merit. We also introduce a criterion that takes into account the robustness of the manufacturing processes to select a geometry that is reliable to manufacture. Finally, we demonstrate that the fabricated grating exhibits the expected optical properties and achieves typical GMOT performance.

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We have observed the decoherence of a lithium atomic wave during its propagation in the presence of the radiation emitted by tungsten-halogen lamps, i.e., decoherence induced by blackbody radiation. We used our atom interferometer to detect this decoherence by measuring the atom fringe-visibility loss. The absorption of a photon excites the atom, which spontaneously emits a fluorescence photon. The momenta of these two photons have random directions, and this random character is the main source of decoherence. All previous similar experiments used small-bandwidth coherent excitation by a laser, whereas incoherent radiation involves several technical and conceptual differences. Our approach is interesting as blackbody radiation is omnipresent and decoherence should be considered if particles resonant to electromagnetic fields are used.

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This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions.

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We report here on the realization of light-pulse atom interferometers with large-momentum-transfer atom optics based on a sequence of Bragg transitions. We demonstrate momentum splitting up to 200 photon recoils in an ultracold atom interferometer. We highlight a new mechanism of destructive interference of the losses leading to a sizable efficiency enhancement of the beam splitters. We perform a comprehensive study of parasitic interferometers due to the inherent multiport feature of the quasi-Bragg pulses. Finally, we experimentally verify the phase shift enhancement and characterize the interferometer visibility loss

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Sujets

Mesures de précision Fringevisibility Magneto-optics Atomic interferometry Detector sensitivity Diffraction de Bragg Atom chip Axion Atomic Bloch states Interférométrie atomique Franges d'interférence Cooling effect Anisotropy Stark effect Condensat de Bose-Einstein Lithium Condensates Fringe visibility Cold atoms CAVITY Dark matter Electro-optics Optique atomique Atom optics Birefringence Aharonov-Bohm effect Atom diffraction Diffraction laser Atom interferometry Parallel velocity Damping Atom interferometer Vibrations Condensats de Bose-Einstein Diffraction atomique par laser Aharonov-Bohm Laser diffraction Atomic polarisability Atomes froids CERN Lab Matter wave Bose-Einstein condensate Frequency doubling Cohérence Non reciprocal effect Lithium atoms Zeeman effect Bose Einstein condensate Coherence Ring cavity Electric polarizability Adsorbats moléculaires Collisions atome-atome Atom interferometers Decoherence Friction He-McKellar-Wilkens ATOMS Close-coupling Experimental results Bragg diffraction Accurate measurement Topological phase Condensats Diffraction Détecteur à fil chaud FIELD Muonic hydrogen Effet Zeeman Birefringences Aharononov-Bohm Effet Aharonov-Bohm Polarizability Fringe contrast Fringe phase shift Cosmic string Black hole Laser cooling of atoms Atom Optics Phase géométrique Experiment Aharonov-Casher Compensation Atom Interferometry Coupled oscillators Effet Stark Optical pumping Interferometry Diffraction d'une onde atomique Diode-pumped solid state lasers Critical phenomena Sagnac effect Polarisabilité Atom inerteferometry Atom Frequency metrology Atome de lithium Amortissement Geometric phases Diffraction atomique

Statistiques

Nombre de fichiers déposés

63

Nombre de notices déposées

44