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

Physical Review Letters

Unity Occupation of Sites in a 3D Optical Lattice

Marshall T. DePue, Colin McCormick, S. Lukman Winoto, Steven J. Oliver, David S. Weiss

Published Mar 15, 1999• 170 citations
Publisher

Abstract

An average filling factor of one atom per lattice site has been obtained in a submicron scale far-off-resonance optical lattice (FORL). High site occupation is obtained through a compression sequence that includes laser cooling in a 3D FORL and adiabatic toggling between the 3D FORL and a 1D FORL trap. After the highest filling factor is achieved, laser cooling causes collisional loss from lattice sites with more than one atom. Ultimately $44%$ of the sites have a single atom cooled to near its vibrational ground state. A theoretical model of site occupation based on Poisson statistics agrees well with the experimental results.

DOI
10.1103/physrevlett.82.2262

Related papers

Laser cooling at high density in deep far-detuned optical lattices

S. Lukman Winoto, Marshall T. DePue, Nathan E. Bramall +1 more

We report a way to overcome heating due to the reabsorption of scattered light when relatively many atoms are laser cooled at high density. A sample of $8\ifmmode\times\else\texttimes\fi{}{10}^{7}\mathrm{Cs}$ atoms, with $6\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{atoms}\mathrm{}\mathrm{cm}}^{\mathrm{\ensuremath{-}}3},$ is loaded into a deep far-detuned one-dimensional optical lattice, which acts as a large volume three-dimensional (3D) trap. Polarization gradient cooling with a separate set of cooling beams is found to work well in this trap, populating the trap's vibrational ground state with more than half the atoms. After cooling, the lattice is shut off adiabatically, leaving a still dense sample at 1.2 \ensuremath{\mu}K. We propose and demonstrate a generalization to a 3D lattice, which will allow many more atoms to be loaded into conservative light traps, and can greatly increase the initial phase-space density for loading magnetic traps.

Physical Review A•Jan 1, 1999•70 citations

Quantum state preparation in an optical lattice

S. E. Hamann

This dissertation reports on quantum state preparation of cesium atoms in a two-dimensional optical lattice, by resolved-sideband Raman cooling. An optical lattice is a periodic potential produced by the light shift interaction between an atom and light field. Laser cooled atoms can become strongly localized about the bottom of potential wells in an optical lattice, where they occupy a discrete spectrum of bound vibrational energy levels. The distribution over vibrational levels of atoms in the lattice is characterized by the mean vibrational excitation, n . In an optical lattice, absorption and emission of photons from lattice beams causes n to increase in time. This source of heating is always present, but its rate can be greatly reduced in a lattice detuned far from the atomic resonance. Sideband cooling is an efficient means of transferring atoms from higher into lower-lying vibrational levels and, thus, it reduces n for the ensemble. If the sideband cooling rate is much greater than the heating rate, then n approaches zero and virtually all atoms are in the lowest vibrational level in their potential wells. Our sideband cooling scheme involves stimulated Raman transitions between bound states in the potential wells of a pair of magnetic sublevels, followed by optical pumping, for a net loss of one quantum of vibration per cooling cycle. The process accumulates 98% of atoms in the ground vibrational level of a potential well associated with a single Zeeman substate. Each atom in the lattice is then very close to a pure state. For two-dimensional lattice with sideband cooling we find nx≈ny≈0.008 &parl0;16&parr0; . Various issues related to state preparation and sideband cooling are also discussed in the context of a one dimensional lin ⊥ lin optical lattice. These include improvement of laser cooling in a near resonance lattice by application of weak magnetic fields, transfer of atoms from near into far off-resonance lattices, and heating rates in far off-resonance lattices.

•Jan 1, 1998•1 citation

Site-Resolved Imaging of Fermionic Li 6 in an Optical Lattice

Maxwell F. Parsons, Florian Huber, Anton Mazurenko +5 more

We demonstrate site-resolved imaging of individual fermionic ^{6}Li atoms in a single layer of a 3D optical lattice. To preserve the density distribution during fluorescence imaging, we simultaneously cool the atoms with 3D Raman sideband cooling. This laser cooling technique, demonstrated here for the first time for ^{6}Li atoms, also provides a pathway to rapid low-entropy filling of an optical lattice. We are able to determine the occupation of individual lattice sites with a fidelity >95%, enabling direct, local measurement of particle correlations in Fermi lattice systems. This ability will be instrumental for creating and investigating low-temperature phases of the Fermi-Hubbard model, including antiferromagnets and d-wave superfluidity.

arXiv:1504.04397•Physical Review Letters•May 28, 2015•338 citations

3D Raman Sideband Cooling of Cesium Atoms at High Density

Dian-Jiun Han, Steffen Wolf, Steven J. Oliver +3 more

We laser cool $5\ifmmode\times\else\texttimes\fi{}{10}^{7}$ Cs atoms to a spin-polarized phase space density of 1/30, the highest ever obtained by laser cooling. It is achieved by compression and polarization gradient cooling in a 3D far-off-resonant optical lattice, followed by 3D Raman sideband cooling optimized at a density of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{12}\mathrm{atoms}/{\mathrm{cm}}^{3}$, and adiabatic release. In the lattice, $23%$ of the sites are occupied, $95%$ of the atoms are in the lowest energy magnetic sublevel, and $37%$ are in the lowest 3D vibrational state.

Physical Review Letters•Jul 24, 2000•108 citations

Cooling atoms in a far-detuned optical lattice

David S. Weiss, S. Lukman Winoto, Mark T. Depue

A new method of studying and cooling trapped atoms is discussed, with particular attention to atoms in far detuned, 3D optical lattices. The technique, projection cooling, uses a combination of microwave and optical fields to cycle atoms between hyperfine sublevels. A single vibrational level will remain dark to both the light and the microwaves, so atoms will accumulate there. Cooling below the photon recoil limit is possible with this technique. As a diagnostic tool it promises to yield detailed information about atoms in the lattice, including vibrational spectra and the distribution of atoms among vibrational levels, even in the limit of relatively weak binding to lattice sites. Atoms cooled in this way and then allowed to adiabatically expand in their potentials could reach the Bose-Einstein condensation point in less than a second, or at least get close enough to reach it after only a modest amount of evaporative cooling in a larger volume trap. Atoms so cooled and trapped are also of interest for precision measurements.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 1, 1997•5 citations

Atom-trapping in the Lamb-Dicke regime in a far-off-resonance optical lattice

D. L. Haycock, S. E. Hamann, Gerd Klose +1 more

We form a 1D optical lattices for Cs atoms using light tuned a few thousand linewidths below the 6S1/2(F equals 4) yields 6P3/2(F' equals 5) transition at 852 nm. In this far-off- resonance lattice the time scale for damping of motional coherences and kinetic energy can be orders of magnitude longer than the vibrational oscillation period for atoms trapped in the lattice potential wells. Atoms are loaded directly into deeply bound states, by adiabatic transfer from a superimposed, near-resonance optical lattice. This yields a mean vibrational excitation n approximately equals 0.3, and localization (Delta) z approximately (lambda) /20 deep in the Lamb-Dicke regime. Light scattering subsequently heats the atoms, but the initial rate is only of order 10-3 vibrational quanta per oscillation period. Low vibrational excitation, localization in the Lamb-Dicke regime and low heating rates make these atoms good candidates for resolved- sideband Raman cooling, and for the generation and study of non-classical states of center-of-mass motion. We propose a scheme for resolved-sideband Raman cooling and quantum state preparation; the scheme employs Raman coupling between magnetic sublevels induced by the lattice light field itself.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 1, 1997•1 citation
An average filling factor of one atom per lattice site has been obtained in a submicron scale far-off-resonance optical lattice (FORL). High site occupation is obtained through a compression sequence that includes laser cooling in a 3D FORL and adiabatic toggling between the 3D FORL and a 1D FORL trap. After the highest filling factor is achieved, laser cooling causes collisional loss from lattice sites with more than one atom. Ultimately 4444%44 of the sites have a single atom cooled to near its vibrational ground state. A theoretical model of site occupation based on Poisson statistics agrees well with the experimental results.
We report a way to overcome heating due to the reabsorption of scattered light when relatively many atoms are laser cooled at high density. A sample of $8\ifmmode\times\else\texttimes\fi{}{10}^{7}\mathrm{Cs}$ atoms, with $6\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{atoms}\mathrm{}\mathrm{cm}}^{\mathrm{\ensuremath{-}}3},$ is loaded into a deep far-detuned one-dimensional optical lattice, which acts as a large volume three-dimensional (3D) trap. Polarization gradient cooling with a separate set of cooling beams is found to work well in this trap, populating the trap's vibrational ground state with more than half the atoms. After cooling, the lattice is shut off adiabatically, leaving a still dense sample at 1.2 \ensuremath{\mu}K. We propose and demonstrate a generalization to a 3D lattice, which will allow many more atoms to be loaded into conservative light traps, and can greatly increase the initial phase-space density for loading magnetic traps.
This dissertation reports on quantum state preparation of cesium atoms in a two-dimensional optical lattice, by resolved-sideband Raman cooling. An optical lattice is a periodic potential produced by the light shift interaction between an atom and light field. Laser cooled atoms can become strongly localized about the bottom of potential wells in an optical lattice, where they occupy a discrete spectrum of bound vibrational energy levels. The distribution over vibrational levels of atoms in the lattice is characterized by the mean vibrational excitation, n . In an optical lattice, absorption and emission of photons from lattice beams causes n to increase in time. This source of heating is always present, but its rate can be greatly reduced in a lattice detuned far from the atomic resonance. Sideband cooling is an efficient means of transferring atoms from higher into lower-lying vibrational levels and, thus, it reduces n for the ensemble. If the sideband cooling rate is much greater than the heating rate, then n approaches zero and virtually all atoms are in the lowest vibrational level in their potential wells. Our sideband cooling scheme involves stimulated Raman transitions between bound states in the potential wells of a pair of magnetic sublevels, followed by optical pumping, for a net loss of one quantum of vibration per cooling cycle. The process accumulates 98% of atoms in the ground vibrational level of a potential well associated with a single Zeeman substate. Each atom in the lattice is then very close to a pure state. For two-dimensional lattice with sideband cooling we find nx≈ny≈0.008 &parl0;16&parr0; . Various issues related to state preparation and sideband cooling are also discussed in the context of a one dimensional lin ⊥ lin optical lattice. These include improvement of laser cooling in a near resonance lattice by application of weak magnetic fields, transfer of atoms from near into far off-resonance lattices, and heating rates in far off-resonance lattices.
We demonstrate site-resolved imaging of individual fermionic ^{6}Li atoms in a single layer of a 3D optical lattice. To preserve the density distribution during fluorescence imaging, we simultaneously cool the atoms with 3D Raman sideband cooling. This laser cooling technique, demonstrated here for the first time for ^{6}Li atoms, also provides a pathway to rapid low-entropy filling of an optical lattice. We are able to determine the occupation of individual lattice sites with a fidelity >95%, enabling direct, local measurement of particle correlations in Fermi lattice systems. This ability will be instrumental for creating and investigating low-temperature phases of the Fermi-Hubbard model, including antiferromagnets and d-wave superfluidity.
We laser cool $5\ifmmode\times\else\texttimes\fi{}{10}^{7}$ Cs atoms to a spin-polarized phase space density of 1/30, the highest ever obtained by laser cooling. It is achieved by compression and polarization gradient cooling in a 3D far-off-resonant optical lattice, followed by 3D Raman sideband cooling optimized at a density of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{12}\mathrm{atoms}/{\mathrm{cm}}^{3}$, and adiabatic release. In the lattice, 2323%23 of the sites are occupied, 9595%95 of the atoms are in the lowest energy magnetic sublevel, and 3737%37 are in the lowest 3D vibrational state.
A new method of studying and cooling trapped atoms is discussed, with particular attention to atoms in far detuned, 3D optical lattices. The technique, projection cooling, uses a combination of microwave and optical fields to cycle atoms between hyperfine sublevels. A single vibrational level will remain dark to both the light and the microwaves, so atoms will accumulate there. Cooling below the photon recoil limit is possible with this technique. As a diagnostic tool it promises to yield detailed information about atoms in the lattice, including vibrational spectra and the distribution of atoms among vibrational levels, even in the limit of relatively weak binding to lattice sites. Atoms cooled in this way and then allowed to adiabatically expand in their potentials could reach the Bose-Einstein condensation point in less than a second, or at least get close enough to reach it after only a modest amount of evaporative cooling in a larger volume trap. Atoms so cooled and trapped are also of interest for precision measurements.
We form a 1D optical lattices for Cs atoms using light tuned a few thousand linewidths below the 6S1/2(F equals 4) yields 6P3/2(F' equals 5) transition at 852 nm. In this far-off- resonance lattice the time scale for damping of motional coherences and kinetic energy can be orders of magnitude longer than the vibrational oscillation period for atoms trapped in the lattice potential wells. Atoms are loaded directly into deeply bound states, by adiabatic transfer from a superimposed, near-resonance optical lattice. This yields a mean vibrational excitation n approximately equals 0.3, and localization (Delta) z approximately (lambda) /20 deep in the Lamb-Dicke regime. Light scattering subsequently heats the atoms, but the initial rate is only of order 10-3 vibrational quanta per oscillation period. Low vibrational excitation, localization in the Lamb-Dicke regime and low heating rates make these atoms good candidates for resolved- sideband Raman cooling, and for the generation and study of non-classical states of center-of-mass motion. We propose a scheme for resolved-sideband Raman cooling and quantum state preparation; the scheme employs Raman coupling between magnetic sublevels induced by the lattice light field itself.