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

Annual Meeting Optical Society of America

Trapped atomic hydrogen

Jon C. Sandberg, John M. Doyle, Ite A. Yu, Claudio Lenz Cesar, Daniel Kleppner, Thomas J. Greytak

Published Jan 1, 1991• 0 citations
Publisher

Abstract

Atomic hydrogen has been loaded into a 1-K deep magnetic trap through the use of a dilution refrigerator. Evaporative cooling has been used to cool the trapped hydrogen into the submillikelvin temperature regime. These techniques have produced a sample with density of 8 × 1013 cm-3 at a temperature of 100 μK. At this density a transition to a Bose-Einstein condensate is predicted to occur at a temperature of 30 μK. These results have been obtained with a magnetic trap that has been constructed to accommodate upcoming experiments based on laser spectroscopy of the 1S-2S two photon transition in the trapped hydrogen. A frequency doubled narrow linewidth cw dye laser system has been constructed to excite the 1S-2S transition. The excitation will be detected by the observation of electric field-induced Lyman-alpha fluorescence. The optical detection system should yield improved sample density and temperature diagnostic capabilities that will facilitate a closer approach to the quantum degenerate regime. Additionally the cold, confined hydrogen gas offers the possibility of improving the level of resolution of Doppler-free hydrogen 1S-2S laser spectroscopy by several orders of magnitude.

DOI
10.1364/oam.1991.tujj2

Related papers

Two-Photon Spectroscopy of Trapped Atomic Hydrogen

Claudio Lenz Cesar, Dale G. Fried, T. C. Killian +6 more

We report observation of the 1S-2S two-photon transition in hydrogen confined in a magnetic trap at submillikelvin temperatures. The excitation spectrum can display a sharp central feature arising from periodic motion of the trapped atoms. The metastable 2S atoms remain trapped, and have a lifetime close to the natural lifetime of 122 ms. These developments open the way to achieving the transition's natural linewidth. We have also demonstrated that the temperature of the gas can be determined from the line shape, providing an important tool for the study of cold trapped hydrogen. The resolution in these experiments appears to be limited by laser stability, currently 3 kHz.

Physical Review Letters•Jul 8, 1996•169 citations

Lyman-α spectroscopy of magnetically trapped atomic hydrogen

O.J. Luiten, H. G. C. Werij, Irwan D. Setija +3 more

We describe the first optical experiments on atomic hydrogen in a magnetic trap, using a narrow-band source at Lyman-\ensuremath{\alpha} wavelength. By means of transmission spectroscopy we have studied the temperature and density evolution of the gas during evaporative cooling in a fixed field geometry.

Physical Review Letters•Feb 1, 1993•50 citations

Towards trapping of hydrogen atoms for computable optical clock applications

Amit, Omer, Taray, Derya, Wirthl, Vitaly +13 more

Because of its simple structure, the hydrogen atom is often used as a testbed for quantum electrodynamics. Spectroscopy of trapped atomic samples can greatly improve the accuracy of these tests. Trapping atomic hydrogen in an optical dipole trap or an optical lattice has never been achieved. Only trapping in magnetic fields that lead to large Zeeman shifts has been demonstrated. Standard techniques of atomic physics are difficult to apply to atomic hydrogen. The small mass of the atom and the large photon energy of the 1S-2P cooling transition significantly complicate Doppler cooling. This proposal introduces a photon recoil-assisted loading scheme that uses these properties to our advantage to load atomic hydrogen into an optical dipole trap without laser cooling. The magic wavelength (515 nm) for the 1S-2S clock transition (1.3-Hz natural linewidth) is easily accessible with current laser technology. Since the 1S-2S clock transition can be driven Doppler free, we do not require a very low temperature. Besides improving spectroscopy for fundamental science, such a system can also be used as a “computable” atomic clock that may one day justify the redefinition of the SI second in terms of the Rydberg constant.

•Sep 1, 2025•0 citations

Spin-polarized hydrogen confined in three and two-dimensions

Isaac F. Silvera

Experimental efforts to produce a Bose Einstein condensed (BEC) gas of spin-polarized atomic hydrogen have been intensely pursued since 1980. Initial efforts studied hydrogen in contact with superfluid helium surfaces. In order to avoid the limiting wall recombination a static magnetic trap was developed which utilizes magnetic barriers to isolate atoms from the van der Wals walls. In this approach traps can be filled to about 10{sup 14} atoms/cm{sup 3} for which the critical temperature is in the region of 20-30 {mu}K. However, approaching BEC conditions, a new instability dominates the behavior. The authors have developed a new type of electromagnetic trap, a microwave (mw) trap in which the trapped atoms are in the ground spin-state so that at low temperature relaxation to a barrier state is strongly suppressed and BEC should be attainable. The shallow mw trap has recently been demonstrated experimentally for the cesium atom. Because the mw trap is so shallow it is necessary to precool the atoms for loading. The authors are constructing a hybrid trap in which the atoms are cooled in a static trap and then transferred to a mw trap where they can be further evaporatively cooled in an effort to achieve BEC.more » This trap should have density limits in the region of 10{sup 16} to 10{sup 17}/cm{sup 3} due to three-body recombination. A second, promising approach is in a 2-D geometry for which in finite sized systems BEC is allowed. Hydrogen atoms are confined to a superfluid helium surface by the absorption potential to form a 2-D gas. Although recombination is an important process on helium surfaces, recently the authors have shown that only a very small fraction of the recombination energy is coupled into the surface. With an appropriate geometry the recombination energy can be removed from the sample region to suppress heating to a negligible level. Furthermore in 2-D a magnetic field can have a maximum so that atoms can be confined to a very small area.« less

Bulletin of the American Physical Society•Apr 1, 1995•0 citations

Ultra Precise Laser Spectroscopy

Daniel Kleppner

Abstract : Research on this AASERT grant was focussed on the optical spectroscopy of trapped cold hydrogen for use as a spectroscopic tool and as a means of studying the gas. The grant supported research by two graduate students. During the grant an optical signal on the 1S - 2S transition in cold trapped hydrogen was observed, opening the way to a new form of ultra high resolution spectroscopy. The optical signal will also provide a valuable tool for manipulating a Bose condensate in hydrogen. The condensate can absorb two photons form a single running wave. The recoil is enough to sweep the atoms out of the trap, creating a new type of atom laser beam.

•Jun 1, 1997•0 citations

Experiments with Atomic Hydrogen in Magnetostatic Traps

Irwan D. Setija, O.J. Luiten, M. W. Reynolds +6 more

Atomic hydrogen is an important model system for the investigation of the properties of ultra‐cold gases. We summarize the current experimental situation for magnetically confined hydrogen, putting emphasis on recent optical experiments with Lyman‐α radiation. As the research is aimed at gas‐phase properties, the samples are studied at densities where interatomic collisions are frequent and internal thermal equilibrium may be assumed. Interestingly, although optically thick, the samples still may be cooled with light. We discuss both Doppler cooling and light induced evaporative cooling.

AIP conference proceedings•Jan 1, 1994•0 citations
Atomic hydrogen has been loaded into a 1-K deep magnetic trap through the use of a dilution refrigerator. Evaporative cooling has been used to cool the trapped hydrogen into the submillikelvin temperature regime. These techniques have produced a sample with density of 8 × 1013 cm-3 at a temperature of 100 μK. At this density a transition to a Bose-Einstein condensate is predicted to occur at a temperature of 30 μK. These results have been obtained with a magnetic trap that has been constructed to accommodate upcoming experiments based on laser spectroscopy of the 1S-2S two photon transition in the trapped hydrogen. A frequency doubled narrow linewidth cw dye laser system has been constructed to excite the 1S-2S transition. The excitation will be detected by the observation of electric field-induced Lyman-alpha fluorescence. The optical detection system should yield improved sample density and temperature diagnostic capabilities that will facilitate a closer approach to the quantum degenerate regime. Additionally the cold, confined hydrogen gas offers the possibility of improving the level of resolution of Doppler-free hydrogen 1S-2S laser spectroscopy by several orders of magnitude.
We report observation of the 1S-2S two-photon transition in hydrogen confined in a magnetic trap at submillikelvin temperatures. The excitation spectrum can display a sharp central feature arising from periodic motion of the trapped atoms. The metastable 2S atoms remain trapped, and have a lifetime close to the natural lifetime of 122 ms. These developments open the way to achieving the transition's natural linewidth. We have also demonstrated that the temperature of the gas can be determined from the line shape, providing an important tool for the study of cold trapped hydrogen. The resolution in these experiments appears to be limited by laser stability, currently 3 kHz.
Because of its simple structure, the hydrogen atom is often used as a testbed for quantum electrodynamics. Spectroscopy of trapped atomic samples can greatly improve the accuracy of these tests. Trapping atomic hydrogen in an optical dipole trap or an optical lattice has never been achieved. Only trapping in magnetic fields that lead to large Zeeman shifts has been demonstrated. Standard techniques of atomic physics are difficult to apply to atomic hydrogen. The small mass of the atom and the large photon energy of the 1S-2P cooling transition significantly complicate Doppler cooling. This proposal introduces a photon recoil-assisted loading scheme that uses these properties to our advantage to load atomic hydrogen into an optical dipole trap without laser cooling. The magic wavelength (515 nm) for the 1S-2S clock transition (1.3-Hz natural linewidth) is easily accessible with current laser technology. Since the 1S-2S clock transition can be driven Doppler free, we do not require a very low temperature. Besides improving spectroscopy for fundamental science, such a system can also be used as a “computable” atomic clock that may one day justify the redefinition of the SI second in terms of the Rydberg constant.
Experimental efforts to produce a Bose Einstein condensed (BEC) gas of spin-polarized atomic hydrogen have been intensely pursued since 1980. Initial efforts studied hydrogen in contact with superfluid helium surfaces. In order to avoid the limiting wall recombination a static magnetic trap was developed which utilizes magnetic barriers to isolate atoms from the van der Wals walls. In this approach traps can be filled to about 10{sup 14} atoms/cm{sup 3} for which the critical temperature is in the region of 20-30 {mu}K. However, approaching BEC conditions, a new instability dominates the behavior. The authors have developed a new type of electromagnetic trap, a microwave (mw) trap in which the trapped atoms are in the ground spin-state so that at low temperature relaxation to a barrier state is strongly suppressed and BEC should be attainable. The shallow mw trap has recently been demonstrated experimentally for the cesium atom. Because the mw trap is so shallow it is necessary to precool the atoms for loading. The authors are constructing a hybrid trap in which the atoms are cooled in a static trap and then transferred to a mw trap where they can be further evaporatively cooled in an effort to achieve BEC.more » This trap should have density limits in the region of 10{sup 16} to 10{sup 17}/cm{sup 3} due to three-body recombination. A second, promising approach is in a 2-D geometry for which in finite sized systems BEC is allowed. Hydrogen atoms are confined to a superfluid helium surface by the absorption potential to form a 2-D gas. Although recombination is an important process on helium surfaces, recently the authors have shown that only a very small fraction of the recombination energy is coupled into the surface. With an appropriate geometry the recombination energy can be removed from the sample region to suppress heating to a negligible level. Furthermore in 2-D a magnetic field can have a maximum so that atoms can be confined to a very small area.« less
Abstract : Research on this AASERT grant was focussed on the optical spectroscopy of trapped cold hydrogen for use as a spectroscopic tool and as a means of studying the gas. The grant supported research by two graduate students. During the grant an optical signal on the 1S - 2S transition in cold trapped hydrogen was observed, opening the way to a new form of ultra high resolution spectroscopy. The optical signal will also provide a valuable tool for manipulating a Bose condensate in hydrogen. The condensate can absorb two photons form a single running wave. The recoil is enough to sweep the atoms out of the trap, creating a new type of atom laser beam.
Atomic hydrogen is an important model system for the investigation of the properties of ultra‐cold gases. We summarize the current experimental situation for magnetically confined hydrogen, putting emphasis on recent optical experiments with Lyman‐α radiation. As the research is aimed at gas‐phase properties, the samples are studied at densities where interatomic collisions are frequent and internal thermal equilibrium may be assumed. Interestingly, although optically thick, the samples still may be cooled with light. We discuss both Doppler cooling and light induced evaporative cooling.