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

DOI: 10.1140/epjd/e2002-00205-1 THE EUROPEAN PHYSICAL JOURNAL D

Published Dec 18, 2014• 0 citations
OpenAlex

Abstract

Abstract. We demonstrate the in situ detection of cold 87Rb atoms near a dielectric surface using the absorption of a weak, resonant evanescent wave. We have used this technique in time of flight experiments determining the density of atoms falling on the surface. A quantitative understanding of the measured curve was obtained using a detailed calculation of the evanescent intensity distribution. We have also used it to detect atoms trapped near the surface in a standing-wave optical dipole potential. This trap was loaded by inelastic bouncing on a strong, repulsive evanescent potential. We estimate that we trap 1:5 104 atoms at a density 100 times higher than the falling atoms. PACS. 32.80.Pj Optical cooling of atoms; trapping { 42.25.Bs Wave propagation, transmission and absorption 1

Related papers

Cold-atom fountain for atom-surface interaction measurements mediated by a near-resonant evanescent light field

Taro Mashimo, Masashi Abe, Athanasios Laliotis +1 more

Cold atomic ensembles offer precise tools for probing near-field interactions, yet experimental data linking atom dynamics to surface-induced forces remains limited. This study investigated the interaction between atoms and a dielectric surface using an atomic fountain measurement technique, in which cold rubidium atoms were released from a moving optical dipole trap. The launched cold atoms were irradiated with an evanescent light detuned from the D$_2$ transition by $-$20.2 to $+$20.2 MHz, after which they were recaptured by reactivating the optical dipole trap. Our measurements revealed that the number of recaptured atoms decreased with increasing flight time, and the decay was suppressed under blue-detuned conditions. We modeled the motion dynamics of the cold atomic ensemble, incorporating Casimir-Polder interactions between the dielectric surface and cold atoms, and observed that the rate of decrease in the number of residual atoms depended on the value of the van der Waals potential coefficient $C_3$. The calculation results demonstrated good agreement with the experimental results, allowing us to estimate $C_3 = 5.6^{+2.4}_{-1.9} \times 10^{-49}$ Jm$^3$ by comparing simulations with the experimental results across various $C_3$ values, accounting for experimental errors.

arXiv:2511.08115•Nov 11, 2025•0 citations

Novel dipole-force atom traps

Inka B. Manek-Hönninger, U. Moslener, Yu. B. Ovchinnikov +5 more

We discuss our recent experimental demonstrations of three novel atom traps which are all based on the optical dipole force in far-detuned laser light. In the gravito-optical surface trap (GOST), Cs atoms are trapped and cooled by means of an evanescent-wave mirror very closely above a dielectric surface. This trap allows for optical cooling at very high densities and provides good starting conditions for evaporative cooling to quantum degeneracy and the realization of a 2D quantum gas. The conical atom trap (CAT) uses a hollow blue-detuned laser beam in combination with gravity to trap atoms in a dark spatial region. This trap is experimentally simple and provides high loading efficiency, tight confinement, efficient sub-Doppler cooling, and strong suppression of collisional losses. The standing-wave red-detuned (STAR) trap allows one to confine atoms in a shallow optical potential at a very low photon scattering rate, and is thus an interesting tool for studies of the atomic ground-state dynamics in external electro-magnetic fields. We have studied atomic spin polarization in this trap.

International Conference on Atomic Physics (ICAP)•Jan 1, 1999•0 citations

Atom traps on an evanescent-wave mirror

Andriy Shevchenko

During the past two decades the dramatic developments in cooling and trapping of gaseous atomic samples has produced a variety of techniques to manipulate the external and internal atomic states with electromagnetic fields. The research efforts so far have mainly focused on studying the fundamental aspects of modern quantum physics, although numerous practical applications, e.g., in integrated matter-wave optics and quantum information processing, are expected to soon be added to the already established atom-optics products, such as atomic clocks and acceleration sensors. One of the most promising foundations for the practical applications of Bose-Einstein condensates (BECs) and coherent matter waves is the technology based on the creation of microscopic atom traps on the surface of a solid substrate. This trapping technique has recently been used to successfully control the motion of microscopic atomic samples and to significantly simplify the creation of BEC.\n\nThe main research topic of this thesis is the development and design of surface-mounted atom traps on transparent dielectric substrates. Such traps could provide an extra flexibility and stability for the experiments, since they would allow unimpeded control of atoms with laser light and provide reduction of magnetic-field fluctuations associated with the thermal motion of free electrons in the substrate material. The thesis describes several novel approaches to the creation of such surface traps by superimposing repulsive evanescent optical waves with strongly localized magnetic or electric fields. These fields can be produced by either conductive or permanently magnetized, optically transparent patterns imprinted in a thin layer on a transparent dielectric substrate. The evanescent wave can also be used to cool the atoms in a gravitational field before loading them into the microtrap. The lateral confinement of the atoms on the evanescent wave can be realized with a thin-walled hollow laser beam, the creation of which is demonstrated in the thesis. The thesis also describes certain general aspects concerning evanescent-wave cooling. In particular, the influence that multiple reabsorption of resonance-frequency photons in a cloud of evanescent-wave cooled atoms has on the cooling efficiency is investigated. Also, a theoretical model based on classical statistical mechanics and thermodynamics is introduced to show how a microtrap on an evanescent-wave mirror can be used to decrease the temperature, increase the phase-space density, and provide temperature conserving spin-polarization of the atoms.

•Oct 8, 2004•1 citation

High-resolution roughness measurements using cold atom reflection

V. Savalli, P. D. Featonby, Vincent Josse +5 more

Summary form only given. Evanescent wave atomic mirrors have been shown to be very sensitive to the surface roughness of the glass substrate on which the evanescent wave is formed. Non-specular reflection of slow atoms at normal incidence has been observed for surface roughness as low as 0.1 nm. We interpret this behaviour in terms of diffraction of the atomic De Broglie wave on the modulated potential created by the interference of the evanescent wave with light scattered by the rough surface. However these experiments could not separate the specular peak of reflected atoms from the diffuse part. We have developed a new method to measure the velocity distribution of the atoms after the bounce with a much better resolution, using Raman transitions. Two phase locked counterpropagating laser beams induce a Raman transition between the ground state hyperfine levels of the /sup 85/Rb atoms falling from a magneto-optical trap. The resonance condition is only fulfilled for atoms with a transverse velocity controlled by the interaction time between the atoms and the beams. These velocity selected atoms bounce on the mirror and their velocity distribution after reflection can be measured using the same Raman beams, by scanning their difference in frequency.

Conference on Lasers and Electro-Optics•Jan 1, 2000•0 citations

Detection of cold metastable atoms at a surface

Dominik Schneble, Masahiro Hasuo, T. Anker +2 more

A scheme for the detection of cold metastable atoms at surfaces with spatial and temporal resolution is studied experimentally, using methods of laser cooling and atom optics. Electron emission yields for deexcitation of the metastable states 1s5(J=2) and 1s3(J=0) of argon at a gold surface are compared with a technique that is based on optical pumping and the use of an evanescent-wave atom mirror as an internal-state filter, and are found to agree to within an uncertainty of 10%. The application of the detection scheme to time-of-flight spectroscopy of cold atom clouds is demonstrated. The detector has a field of view of 3 mm diameter, a spatial resolution of order 100 μm, and a time resolution of 20 μs, and the single-atom detection efficiency near the center of the field of view is 14% in the linear counting regime of up to 106 atoms/s.

Review of Scientific Instruments•May 1, 2003•5 citations

Observation of modified radiative properties of cold atoms in vacuum near a dielectric surface

V V Ivanov, R A Cornelussen, H. B. van Linden van den Heuvell +1 more

We have observed a distance-dependent absorption linewidth of cold $^{87}$Rb atoms close to a dielectric-vacuum interface. This is the first observation of modified radiative properties in vacuum near a dielectric surface. A cloud of cold atoms was created using a magneto-optical trap (MOT) and optical molasses cooling. Evanescent waves (EW) were used to observe the behavior of the atoms near the surface. We observed an increase of the absorption linewidth with up to 25% with respect to the free-space value. Approximately half the broadening can be explained by cavity-quantum electrodynamics (CQED) as an increase of the natural linewidth and inhomogeneous broadening. The remainder we attribute to local Stark shifts near the surface. By varying the characteristic EW length we have observed a distance dependence characteristic for CQED.

arXiv:physics/0407051•Journal of Optics B Quantum and Semiclassical Optics•Sep 18, 2004•16 citations
Abstract. We demonstrate the in situ detection of cold 87Rb atoms near a dielectric surface using the absorption of a weak, resonant evanescent wave. We have used this technique in time of flight experiments determining the density of atoms falling on the surface. A quantitative understanding of the measured curve was obtained using a detailed calculation of the evanescent intensity distribution. We have also used it to detect atoms trapped near the surface in a standing-wave optical dipole potential. This trap was loaded by inelastic bouncing on a strong, repulsive evanescent potential. We estimate that we trap 1:5 104 atoms at a density 100 times higher than the falling atoms. PACS. 32.80.Pj Optical cooling of atoms; trapping { 42.25.Bs Wave propagation, transmission and absorption 1
Cold atomic ensembles offer precise tools for probing near-field interactions, yet experimental data linking atom dynamics to surface-induced forces remains limited. This study investigated the interaction between atoms and a dielectric surface using an atomic fountain measurement technique, in which cold rubidium atoms were released from a moving optical dipole trap. The launched cold atoms were irradiated with an evanescent light detuned from the D2_22​ transition by $-$20.2 to $+$20.2 MHz, after which they were recaptured by reactivating the optical dipole trap. Our measurements revealed that the number of recaptured atoms decreased with increasing flight time, and the decay was suppressed under blue-detuned conditions. We modeled the motion dynamics of the cold atomic ensemble, incorporating Casimir-Polder interactions between the dielectric surface and cold atoms, and observed that the rate of decrease in the number of residual atoms depended on the value of the van der Waals potential coefficient C3C_3C3​. The calculation results demonstrated good agreement with the experimental results, allowing us to estimate C3=5.6−1.9+2.4×10−49C_3 = 5.6^{+2.4}_{-1.9} \times 10^{-49}C3​=5.6−1.9+2.4​×10−49 Jm3^33 by comparing simulations with the experimental results across various C3C_3C3​ values, accounting for experimental errors.
We discuss our recent experimental demonstrations of three novel atom traps which are all based on the optical dipole force in far-detuned laser light. In the gravito-optical surface trap (GOST), Cs atoms are trapped and cooled by means of an evanescent-wave mirror very closely above a dielectric surface. This trap allows for optical cooling at very high densities and provides good starting conditions for evaporative cooling to quantum degeneracy and the realization of a 2D quantum gas. The conical atom trap (CAT) uses a hollow blue-detuned laser beam in combination with gravity to trap atoms in a dark spatial region. This trap is experimentally simple and provides high loading efficiency, tight confinement, efficient sub-Doppler cooling, and strong suppression of collisional losses. The standing-wave red-detuned (STAR) trap allows one to confine atoms in a shallow optical potential at a very low photon scattering rate, and is thus an interesting tool for studies of the atomic ground-state dynamics in external electro-magnetic fields. We have studied atomic spin polarization in this trap.
During the past two decades the dramatic developments in cooling and trapping of gaseous atomic samples has produced a variety of techniques to manipulate the external and internal atomic states with electromagnetic fields. The research efforts so far have mainly focused on studying the fundamental aspects of modern quantum physics, although numerous practical applications, e.g., in integrated matter-wave optics and quantum information processing, are expected to soon be added to the already established atom-optics products, such as atomic clocks and acceleration sensors. One of the most promising foundations for the practical applications of Bose-Einstein condensates (BECs) and coherent matter waves is the technology based on the creation of microscopic atom traps on the surface of a solid substrate. This trapping technique has recently been used to successfully control the motion of microscopic atomic samples and to significantly simplify the creation of BEC.\n\nThe main research topic of this thesis is the development and design of surface-mounted atom traps on transparent dielectric substrates. Such traps could provide an extra flexibility and stability for the experiments, since they would allow unimpeded control of atoms with laser light and provide reduction of magnetic-field fluctuations associated with the thermal motion of free electrons in the substrate material. The thesis describes several novel approaches to the creation of such surface traps by superimposing repulsive evanescent optical waves with strongly localized magnetic or electric fields. These fields can be produced by either conductive or permanently magnetized, optically transparent patterns imprinted in a thin layer on a transparent dielectric substrate. The evanescent wave can also be used to cool the atoms in a gravitational field before loading them into the microtrap. The lateral confinement of the atoms on the evanescent wave can be realized with a thin-walled hollow laser beam, the creation of which is demonstrated in the thesis. The thesis also describes certain general aspects concerning evanescent-wave cooling. In particular, the influence that multiple reabsorption of resonance-frequency photons in a cloud of evanescent-wave cooled atoms has on the cooling efficiency is investigated. Also, a theoretical model based on classical statistical mechanics and thermodynamics is introduced to show how a microtrap on an evanescent-wave mirror can be used to decrease the temperature, increase the phase-space density, and provide temperature conserving spin-polarization of the atoms.
Summary form only given. Evanescent wave atomic mirrors have been shown to be very sensitive to the surface roughness of the glass substrate on which the evanescent wave is formed. Non-specular reflection of slow atoms at normal incidence has been observed for surface roughness as low as 0.1 nm. We interpret this behaviour in terms of diffraction of the atomic De Broglie wave on the modulated potential created by the interference of the evanescent wave with light scattered by the rough surface. However these experiments could not separate the specular peak of reflected atoms from the diffuse part. We have developed a new method to measure the velocity distribution of the atoms after the bounce with a much better resolution, using Raman transitions. Two phase locked counterpropagating laser beams induce a Raman transition between the ground state hyperfine levels of the /sup 85/Rb atoms falling from a magneto-optical trap. The resonance condition is only fulfilled for atoms with a transverse velocity controlled by the interaction time between the atoms and the beams. These velocity selected atoms bounce on the mirror and their velocity distribution after reflection can be measured using the same Raman beams, by scanning their difference in frequency.
A scheme for the detection of cold metastable atoms at surfaces with spatial and temporal resolution is studied experimentally, using methods of laser cooling and atom optics. Electron emission yields for deexcitation of the metastable states 1s5(J=2) and 1s3(J=0) of argon at a gold surface are compared with a technique that is based on optical pumping and the use of an evanescent-wave atom mirror as an internal-state filter, and are found to agree to within an uncertainty of 10%. The application of the detection scheme to time-of-flight spectroscopy of cold atom clouds is demonstrated. The detector has a field of view of 3 mm diameter, a spatial resolution of order 100 μm, and a time resolution of 20 μs, and the single-atom detection efficiency near the center of the field of view is 14% in the linear counting regime of up to 106 atoms/s.
We have observed a distance-dependent absorption linewidth of cold 87^{87}87Rb atoms close to a dielectric-vacuum interface. This is the first observation of modified radiative properties in vacuum near a dielectric surface. A cloud of cold atoms was created using a magneto-optical trap (MOT) and optical molasses cooling. Evanescent waves (EW) were used to observe the behavior of the atoms near the surface. We observed an increase of the absorption linewidth with up to 25% with respect to the free-space value. Approximately half the broadening can be explained by cavity-quantum electrodynamics (CQED) as an increase of the natural linewidth and inhomogeneous broadening. The remainder we attribute to local Stark shifts near the surface. By varying the characteristic EW length we have observed a distance dependence characteristic for CQED.