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

Cooling and Localization Dynamics in Optical Lattices

Georg A. Raithel, G. Birkl, Anders Kastberg, William D. Phillips, S. L. Rolston

Published Jan 27, 1997• 87 citations
Publisher

Abstract

Using Bragg scattering as a sensitive probe, we study how atoms are cooled and localized after the sudden turn-on of 1D and 3D optical lattices. We measure the time evolution of the mean-square position spread of the atoms in the lattice potential wells, a quantity proportional to their effective temperature. The rate of exponential approach to equilibrium is proportional to the photon scattering rate and about 6 times faster in 1D than in 3D. This simple proportionality was unexpected, based on the usual model of Sisyphus cooling, but is in agreement with our 1D Monte Carlo simulations.

DOI
10.1103/physrevlett.78.630

Related papers

Time dependence of laser cooling in optical lattices

Claude M. Dion, Peder Sjölund, S.J.H. Petra +2 more

We study the dynamics of the cooling of a gas of caesium atoms in an optical lattice, both experimentally and with 1D full-quantum Monte Carlo simulations. We find that, contrary to the standard interpretation of the Sisyphus model, the cooling process does not work by a continuous decrease of the average kinetic energy of the atoms in the lattice. Instead, we show that the momentum of the atoms follows a bimodal distribution, the atoms being gradually transferred from a hot to a cold mode. We suggest that the cooling mechanism should be depicted in terms of a rate model, describing the transfer between the two modes along with the processes occurring within each mode.

arXiv:physics/0506119•Europhysics Letters (EPL)•Sep 22, 2005•10 citations

Temperature and optical pumping rates in a bichromatic 3D Optical Lattice

Harald Ellmann, Johan Jersblad, Anders Kastberg

A complete laser cooling setup was built, with focus on threedimensional near-resonant optical lattices for cesium. These consist of regularly ordered micropotentials, created by the interference of four laser beams. One key feature of optical lattices is an inherent ”Sisyphus cooling” process. It efficiently extracts kinetic energy from the atoms, leading to equilibrium temperatures of a few µK. The corresponding kinetic energy is lower than the depth of the potential wells, so that atoms can be trapped.We performed detailed studies of the cooling processes in optical lattices by using the time-of-flight and absorption-imaging techniques. We investigated the dependence of the equilibrium temperature on the optical lattice parameters, such as detuning, optical potential and lattice geometry. The presence of neighbouring transitions in the cesium hyperfine level structure was used to break symmetries in order to identify, which role “red” and “blue” transitions play in the cooling. We also examined the limits for the cooling process in optical lattices, and the possible difference in steady-state velocity distributions for different directions. Moreover, in collaboration with ´Ecole Normale Sup´erieure in Paris, numerical simulations were performed in order to get more insight in the cooling dynamics of optical lattices.Optical lattices can keep atoms almost perfectly isolated from the environment and have therefore been suggested as a platform for a host of possible experiments aimed at coherent quantum manipulations, such as spin-squeezing and the implementation of quantum logic-gates. We developed a novel way to trap two different cesium ground states in two distinct, interpenetrating optical lattices, and to change the distance between sites of one lattice relative to sites of the other lattice. This is a first step towards the implementation of quantum simulation schemes in optical lattices.

•Jan 1, 2002•0 citations

Quantum Phases of Matter in Optical Lattices

Han Pu, Randall G. Hulet

Abstract : Ultracold atoms confined in optical lattice potentials provide an ideal platform to address some of the most outstanding questions in quantum many-body physics, that are difficult or impossible to study using conventional solid state systems. During this DARPA program, progressin several important directions has been made. We have developed cooling techniques suitable for a lattice system and cooled fermionic lithium atoms confined in a three-dimensional (3D) cubic lattice to unprecedented low temperatures, very close to the Neel temperature. We employed Bragg scattering of near-resonant light to observe the antiferromagnetic correlations. We have mapped the phase diagram overthe entire BEC-BCS crossover for a trapped 3D gas with imbalanced numbers of spin-up and spin-down atoms, and have also observed the crossover from a 1D to a 3D spin-imbalanced Fermi gas. We have investigated dynamics, rethermalization and out-of-equilibrium phenomena in strongly correlated lattice systems, as well as in disordered lattice systems. These studies greatly deepened our understanding of quantum phases of matter in lattice potentials.

•Jun 30, 2015•0 citations

Temperature and localization of atoms in three-dimensional optical lattices

M. Gatzke, G. Birkl, Poul Jessen +3 more

We report temperature measurements of atoms trapped in a three-dimensional (3D) optical lattice, a well-defined laser-cooling situation that can be treated with currently available theoretical tools. We also obtain fluorescence spectra from a 3D optical lattice, from which we obtain quantitative information about the trapping atoms, including the oscillation frequencies, spatial localization, and a temperature, which is in good agreement with our direct measurements. For comparison we study a 1D lattice using the same atom (cesium).

Physical Review A•Jun 1, 1997•37 citations

Adiabatic Cooling of Cesium to 700 nK in an Optical Lattice

Anders Kastberg, William D. Phillips, S. L. Rolston +2 more

We localize Cs atoms in wavelength-sized potential wells of an optical lattice, and cool them to a three-dimensional temperature of 700 nK by adiabatic expansion. In the optical lattice we precool the atoms to $\ensuremath{\approx}1\ensuremath{\mu}\mathrm{K}$. We then reduce the trapping potential in a few hundred $\ensuremath{\mu}$s, causing the atomic center-of-mass distribution to expand and the temperature to decrease by an amount which agrees with a simple 3D band theory. These are the lowest 3D kinetic temperatures ever measured.

Physical Review Letters•Feb 27, 1995•260 citations

Magnetization and spin-flip dynamics of atoms in optical lattices

Georg A. Raithel, William D. Phillips, S. L. Rolston

We show, experimentally and using quantum Monte Carlo simulations, that the quasithermal paramagnetic behavior of cesium atoms in a one-dimensional $\mathrm{lin}\mathrm{\ensuremath{\perp}}\mathrm{lin}$ optical lattice is characterized by a spin temperature of twice the zero-field kinetic temperature. The magnetization is maximum and almost perfect when the Zeeman shift of the extreme magnetic sublevels approximately equals half the maximum light shift. The lifetime of magnetization and the laser-cooling time constant are found to be clearly distinct, the magnetization decay time amounting to at least three times the cooling time. Using simulations we find that the magnetic-dipole correlation time is approximately proportional to the angular momentum $F$ of the atoms, while cooling and energy correlation time constants are approximately independent of $F.$ Our results imply that for large $F$ laser cooling within single light-shift potential wells (local cooling) occurs.

Physical Review A•Oct 1, 1998•7 citations
Using Bragg scattering as a sensitive probe, we study how atoms are cooled and localized after the sudden turn-on of 1D and 3D optical lattices. We measure the time evolution of the mean-square position spread of the atoms in the lattice potential wells, a quantity proportional to their effective temperature. The rate of exponential approach to equilibrium is proportional to the photon scattering rate and about 6 times faster in 1D than in 3D. This simple proportionality was unexpected, based on the usual model of Sisyphus cooling, but is in agreement with our 1D Monte Carlo simulations.
We study the dynamics of the cooling of a gas of caesium atoms in an optical lattice, both experimentally and with 1D full-quantum Monte Carlo simulations. We find that, contrary to the standard interpretation of the Sisyphus model, the cooling process does not work by a continuous decrease of the average kinetic energy of the atoms in the lattice. Instead, we show that the momentum of the atoms follows a bimodal distribution, the atoms being gradually transferred from a hot to a cold mode. We suggest that the cooling mechanism should be depicted in terms of a rate model, describing the transfer between the two modes along with the processes occurring within each mode.
A complete laser cooling setup was built, with focus on threedimensional near-resonant optical lattices for cesium. These consist of regularly ordered micropotentials, created by the interference of four laser beams. One key feature of optical lattices is an inherent ”Sisyphus cooling” process. It efficiently extracts kinetic energy from the atoms, leading to equilibrium temperatures of a few µK. The corresponding kinetic energy is lower than the depth of the potential wells, so that atoms can be trapped.We performed detailed studies of the cooling processes in optical lattices by using the time-of-flight and absorption-imaging techniques. We investigated the dependence of the equilibrium temperature on the optical lattice parameters, such as detuning, optical potential and lattice geometry. The presence of neighbouring transitions in the cesium hyperfine level structure was used to break symmetries in order to identify, which role “red” and “blue” transitions play in the cooling. We also examined the limits for the cooling process in optical lattices, and the possible difference in steady-state velocity distributions for different directions. Moreover, in collaboration with ´Ecole Normale Sup´erieure in Paris, numerical simulations were performed in order to get more insight in the cooling dynamics of optical lattices.Optical lattices can keep atoms almost perfectly isolated from the environment and have therefore been suggested as a platform for a host of possible experiments aimed at coherent quantum manipulations, such as spin-squeezing and the implementation of quantum logic-gates. We developed a novel way to trap two different cesium ground states in two distinct, interpenetrating optical lattices, and to change the distance between sites of one lattice relative to sites of the other lattice. This is a first step towards the implementation of quantum simulation schemes in optical lattices.
Abstract : Ultracold atoms confined in optical lattice potentials provide an ideal platform to address some of the most outstanding questions in quantum many-body physics, that are difficult or impossible to study using conventional solid state systems. During this DARPA program, progressin several important directions has been made. We have developed cooling techniques suitable for a lattice system and cooled fermionic lithium atoms confined in a three-dimensional (3D) cubic lattice to unprecedented low temperatures, very close to the Neel temperature. We employed Bragg scattering of near-resonant light to observe the antiferromagnetic correlations. We have mapped the phase diagram overthe entire BEC-BCS crossover for a trapped 3D gas with imbalanced numbers of spin-up and spin-down atoms, and have also observed the crossover from a 1D to a 3D spin-imbalanced Fermi gas. We have investigated dynamics, rethermalization and out-of-equilibrium phenomena in strongly correlated lattice systems, as well as in disordered lattice systems. These studies greatly deepened our understanding of quantum phases of matter in lattice potentials.
We report temperature measurements of atoms trapped in a three-dimensional (3D) optical lattice, a well-defined laser-cooling situation that can be treated with currently available theoretical tools. We also obtain fluorescence spectra from a 3D optical lattice, from which we obtain quantitative information about the trapping atoms, including the oscillation frequencies, spatial localization, and a temperature, which is in good agreement with our direct measurements. For comparison we study a 1D lattice using the same atom (cesium).
We localize Cs atoms in wavelength-sized potential wells of an optical lattice, and cool them to a three-dimensional temperature of 700 nK by adiabatic expansion. In the optical lattice we precool the atoms to $\ensuremath{\approx}1\ensuremath{\mu}\mathrm{K}$. We then reduce the trapping potential in a few hundred $\ensuremath{\mu}$s, causing the atomic center-of-mass distribution to expand and the temperature to decrease by an amount which agrees with a simple 3D band theory. These are the lowest 3D kinetic temperatures ever measured.
We show, experimentally and using quantum Monte Carlo simulations, that the quasithermal paramagnetic behavior of cesium atoms in a one-dimensional $\mathrm{lin}\mathrm{\ensuremath{\perp}}\mathrm{lin}$ optical lattice is characterized by a spin temperature of twice the zero-field kinetic temperature. The magnetization is maximum and almost perfect when the Zeeman shift of the extreme magnetic sublevels approximately equals half the maximum light shift. The lifetime of magnetization and the laser-cooling time constant are found to be clearly distinct, the magnetization decay time amounting to at least three times the cooling time. Using simulations we find that the magnetic-dipole correlation time is approximately proportional to the angular momentum FFF of the atoms, while cooling and energy correlation time constants are approximately independent of F.F.F. Our results imply that for large FFF laser cooling within single light-shift potential wells (local cooling) occurs.