Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Beam propagation in magnetic atomic guides

Karen Rodríguez, Ángela M. Guzmán

Published Oct 21, 2004• 0 citations
Publisher

Abstract

We study modal propagation of cold atomic gases in a straight magnetic waveguide consisting of a current wire and a uniform magnetic field. This configuration is known to generate a transverse confining potential for atoms with magnetic dipole moment oriented anti-parallel to the magnetic field. The potential has azimuthal symmetry to first order in powers of the atomic distance to the waveguide axis. We obtain the modal dispersion curves by means of the WKB quantization method, and introduce a parameter Q that characterizes symmetric atomic waveguides as the parameter V does in optical fibers. We simulate propagation of cold atomic beams by means of the BPM (Beam Propagation Method) and show the spatial evolution of transverse monomode and multimode profiles obtained for different values of Q and arbitrary input beam profiles. We demonstrate, analytically and numerically, the existence of a threshold Q-value for guidance of matter waves analogous to the V-threshold for propagation in a TE00 mode in optical fibers and obtain that, under the experimental conditions reported in the literature, the already observed Gaussian profile of guided atomic beams corresponds to multimode propagation. RIAO/OPTILAS'04.

DOI
10.1117/12.590684

Related papers

Beam propagation in symmetric magnetic atomic guides

Karen Rodriguez, Ángela M. Guzmán

Modal propagation constants for a magnetic atomic waveguide are obtained by WKB quantization. Propagation of cold atomic beams with Gaussian input transverse profile is simulated with the BPM (Beam Propagation Method). The spatial evolution of transverse monomode and multimode profiles is shown. Multimode Gaussian propagation corresponds to reported experimental conditions.

Frontiers in Optics•Jan 1, 2004•0 citations

Beam propagation in atomic waveguides

E. Arevalo, Ángela M. Guzmán

We perform modal analysis and ultracold atomic beam propagation in hollow optical fibers. The eigenmodes and modal propagation constants of the atomic waveguide are determined by numerical solution of the Schrodinger equation for the center-of-mass motion. The existence of a threshold de Broglie wavelength for the fundamental mode is predicted. Beam propagation is performed by modal expansion of the wavefunction on a truncated basis of eigenmodes of the atomic waveguide. The evolution of the atomic probability density profile along the waveguide for a non cylindrical atomic beam is shown.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jul 6, 1999•0 citations

Cold atom dynamics in atomic waveguides and optical lattices.

Boon-Keng Kevin Teo

We have constructed a tapered magnetic atom guide that is integrated with a magneto-optical trap. We have observed atom guiding over distances of up to 20 cm. This integrated strategy is useful for loading atoms into wire guides. We have shown that tapered sections in atom guides. i.e. sections with a variable steepness of the transverse guiding potential, can reflect atoms propagating in the guide. The reflection arises from the adiabatic conservation of the action of the transverse motion; the latter can be used as a control parameter for the atom reflectivity. A method of producing a slow, dark atomic beam of atoms is demonstrated. Atoms that are extracted from a magneto-optical trap using a push beam are quickly pumped into a dark state, which does not interact with the push laser beam. This method is capable of producing atoms with a velocity of order 1 m/s. The slow atoms can be coupled into atom guides. In related research, we observe tunneling resonances of atoms in a 1D optical lattice through the measurement of the magnetization. These resonances manifest themselves as modulations in the magnetization curves. The resonances are shown to be related to the coherence properties of the atoms, and exist only under conditions where the coherence time exceeds the tunneling period of the atoms.

•Jan 1, 2002•0 citations

A miniature magnetic waveguide for cold atoms

Moe Key

This thesis presents the first demonstration of a guide for cold atoms based on a miniature structure of four current-carrying wires. The four wires are embedded within a hollow silica fibre. Atoms are guided along the centre of a fifth hole on the axis of the fibre by the Stern-Gerlach force. A vapour cell Magneto Optical Trap (MOT), formed 1 cm above the mouth of the waveguide is the source of cold "8"5Rb atoms. After cooling the atoms to 25 #mu#K in optical molasses they fall under the influence of gravity through a magnetic funnel into the waveguide. After propagating for 2 cm, the atoms are reflected by the field of a small pinch coil wound around the base of the guide. The atoms then travel back up the fibre and out into the funnel, where they can be imaged either in fluorescence or by recapturing in the MOT. A video sequence of atoms falling into the guide and re-emerging after reflection from the pinch coil graphically illustrates the operation of the guide. The coupling efficiency and transverse temperature of the atoms is measured experimentally and in a Monte-Carlo simulation. We find an optimum coupling efficiency of 12% and we measure the spatial extent of the cloud within the fibre to be of order 100 #mu#m. We find good agreement between experimental data and results from the numerical simulation. We have also been able to observe different thresholds for the reflection of different positive m_F levels. In another experiment we are able to trap the atoms in an elongated Ioffe trap for up to two seconds, increasing the distance over which the atoms are guided. We are able to guide the atoms over distances of 40 cm with a loss rate indistinguishable from the free space loss rate. (author)

•Sep 1, 2000•0 citations

Propagation of Cold Atoms along a Miniature Magnetic Guide

M. Key, Ifan G. Hughes, Wilbert Rooijakkers +4 more

A cloud of laser-cooled 85Rb atoms is coupled through a magnetic funnel into a miniature waveguide formed by four current-carrying wires embedded in a silica fiber. The atom cloud has a approximately 100 &mgr;m radius within the fiber and propagates over cm distances. We study the coupling, propagation, and transverse distribution of atoms in the fiber, and find good agreement with theory. This prototype demonstrates the feasibility of miniature guides as a tool in the new field of integrated atom optics, leading to single-mode propagation of de Broglie waves and the possible preparation of 1D atom clouds.

Physical Review Letters•Feb 14, 2000•152 citations

Transverse mode imaging of guided matter waves

R. G. Dall, Sean S. Hodgman, Mattias Johnsson +2 more

Ultracold atoms whose de Broglie wavelength is of the same order as an extended confining potential can experience waveguiding along the potential. When the transverse kinetic energy of the atoms is sufficiently low, they can be guided in the lowest order mode of the confining potential by analogy with light guided by a single mode optical fiber. We have obtained the first images of the transverse mode structure of guided matter waves in a confining potential with up to $65%$ of atoms in the lowest order mode. The coherence of the guided atomic de Broglie waves is demonstrated by the diffraction pattern produced when incident upon a two dimensional periodic structure. Such coherent waveguides will be important atom optic components in devices with applications such as atom holography and atom interferometry.

Physical Review A•Jan 7, 2010•20 citations
We study modal propagation of cold atomic gases in a straight magnetic waveguide consisting of a current wire and a uniform magnetic field. This configuration is known to generate a transverse confining potential for atoms with magnetic dipole moment oriented anti-parallel to the magnetic field. The potential has azimuthal symmetry to first order in powers of the atomic distance to the waveguide axis. We obtain the modal dispersion curves by means of the WKB quantization method, and introduce a parameter Q that characterizes symmetric atomic waveguides as the parameter V does in optical fibers. We simulate propagation of cold atomic beams by means of the BPM (Beam Propagation Method) and show the spatial evolution of transverse monomode and multimode profiles obtained for different values of Q and arbitrary input beam profiles. We demonstrate, analytically and numerically, the existence of a threshold Q-value for guidance of matter waves analogous to the V-threshold for propagation in a TE00 mode in optical fibers and obtain that, under the experimental conditions reported in the literature, the already observed Gaussian profile of guided atomic beams corresponds to multimode propagation. RIAO/OPTILAS'04.
We perform modal analysis and ultracold atomic beam propagation in hollow optical fibers. The eigenmodes and modal propagation constants of the atomic waveguide are determined by numerical solution of the Schrodinger equation for the center-of-mass motion. The existence of a threshold de Broglie wavelength for the fundamental mode is predicted. Beam propagation is performed by modal expansion of the wavefunction on a truncated basis of eigenmodes of the atomic waveguide. The evolution of the atomic probability density profile along the waveguide for a non cylindrical atomic beam is shown.
We have constructed a tapered magnetic atom guide that is integrated with a magneto-optical trap. We have observed atom guiding over distances of up to 20 cm. This integrated strategy is useful for loading atoms into wire guides. We have shown that tapered sections in atom guides. i.e. sections with a variable steepness of the transverse guiding potential, can reflect atoms propagating in the guide. The reflection arises from the adiabatic conservation of the action of the transverse motion; the latter can be used as a control parameter for the atom reflectivity. A method of producing a slow, dark atomic beam of atoms is demonstrated. Atoms that are extracted from a magneto-optical trap using a push beam are quickly pumped into a dark state, which does not interact with the push laser beam. This method is capable of producing atoms with a velocity of order 1 m/s. The slow atoms can be coupled into atom guides. In related research, we observe tunneling resonances of atoms in a 1D optical lattice through the measurement of the magnetization. These resonances manifest themselves as modulations in the magnetization curves. The resonances are shown to be related to the coherence properties of the atoms, and exist only under conditions where the coherence time exceeds the tunneling period of the atoms.
This thesis presents the first demonstration of a guide for cold atoms based on a miniature structure of four current-carrying wires. The four wires are embedded within a hollow silica fibre. Atoms are guided along the centre of a fifth hole on the axis of the fibre by the Stern-Gerlach force. A vapour cell Magneto Optical Trap (MOT), formed 1 cm above the mouth of the waveguide is the source of cold "8"5Rb atoms. After cooling the atoms to 25 #mu#K in optical molasses they fall under the influence of gravity through a magnetic funnel into the waveguide. After propagating for 2 cm, the atoms are reflected by the field of a small pinch coil wound around the base of the guide. The atoms then travel back up the fibre and out into the funnel, where they can be imaged either in fluorescence or by recapturing in the MOT. A video sequence of atoms falling into the guide and re-emerging after reflection from the pinch coil graphically illustrates the operation of the guide. The coupling efficiency and transverse temperature of the atoms is measured experimentally and in a Monte-Carlo simulation. We find an optimum coupling efficiency of 12% and we measure the spatial extent of the cloud within the fibre to be of order 100 #mu#m. We find good agreement between experimental data and results from the numerical simulation. We have also been able to observe different thresholds for the reflection of different positive m_F levels. In another experiment we are able to trap the atoms in an elongated Ioffe trap for up to two seconds, increasing the distance over which the atoms are guided. We are able to guide the atoms over distances of 40 cm with a loss rate indistinguishable from the free space loss rate. (author)
A cloud of laser-cooled 85Rb atoms is coupled through a magnetic funnel into a miniature waveguide formed by four current-carrying wires embedded in a silica fiber. The atom cloud has a approximately 100 &mgr;m radius within the fiber and propagates over cm distances. We study the coupling, propagation, and transverse distribution of atoms in the fiber, and find good agreement with theory. This prototype demonstrates the feasibility of miniature guides as a tool in the new field of integrated atom optics, leading to single-mode propagation of de Broglie waves and the possible preparation of 1D atom clouds.
Ultracold atoms whose de Broglie wavelength is of the same order as an extended confining potential can experience waveguiding along the potential. When the transverse kinetic energy of the atoms is sufficiently low, they can be guided in the lowest order mode of the confining potential by analogy with light guided by a single mode optical fiber. We have obtained the first images of the transverse mode structure of guided matter waves in a confining potential with up to 6565%65 of atoms in the lowest order mode. The coherence of the guided atomic de Broglie waves is demonstrated by the diffraction pattern produced when incident upon a two dimensional periodic structure. Such coherent waveguides will be important atom optic components in devices with applications such as atom holography and atom interferometry.