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

arXiv:quant-ph/9808014 · Physical Review A

Dynamical cooling of trapped gases: One-atom problem

Luis Santos, Maciej Lewenstein

Published Jan 1, 1999• 9 citations
arXivHTMLPDF

Abstract

We study the laser cooling of one atom in a harmonic trap beyond the Lamb-Dicke regime. By using sequences of laser pulses of different detunings we show that the atom can be confined into just one state of the trap, either the ground state or an excited state of the harmonic potential. The latter can be achieved because under certain conditions an excited state becomes a dark state. We study the problem in one and two dimensions. For the latter case a different cooling mechanism is possible, based on the destructive interference between the effects of laser fields in different directions, which allows the creation of a variety of dark states. For both, one- and two-dimensional cases, Monte Carlo simulations of the cooling dynamics are presented.

DOI
10.1103/physreva.59.613

Related papers

Dynamical cooling of trapped gases. II: Many-atom problem

Luis Santos, Maciej Lewenstein

We analyze the laser cooling of trapped bosonic gases beyond the Lamb-Dicke limit. We use a quantum master equation formalism to study the cooling dynamics, and show that dark-state cooling methods similar to those previously proposed for a single trapped atom allow for the condensation of a collection of bosons into a single state of the trap, either the ground state or an excited state. Using Monte Carlo simulations we analyze the condensation dynamics for different dimensions, and two different cooling schemes; we also demonstrate the appearance of multistability and hysteresis phenomena.

Physical Review A•Nov 1, 1999•15 citations

Laser cooling of trapped atoms to the ground state: A dark state in position space

Giovanna Morigi, J. I. Cirac, K. Ellinger +1 more

We propose a scheme that allows us to laser cool trapped atoms to the ground state of a one-dimensional confining potential. The scheme is based on the creation of a dark state by designing the laser profile, so that the hottest atoms are coherently pumped to another internal level, and then repumped back. The scheme works beyond the Lamb-Dicke limit. We present results of a full quantum treatment for a one-dimensional model.

arXiv:quant-ph/9710034•Physical Review A•Apr 1, 1998•18 citations

Laser cooling of two trapped ions: Sideband cooling beyond the Lamb-Dicke limit

Giovanna Morigi, Jürgen Eschner, J. I. Cirac +1 more

We study laser cooling of two ions that are trapped in a harmonic potential and interact by Coulomb repulsion. Sideband cooling in the Lamb-Dicke regime is shown to work analogously to sideband cooling of a single ion. Outside the Lamb-Dicke regime, the incommensurable frequencies of the two vibrational modes result in a quasicontinuous energy spectrum that significantly alters the cooling dynamics. The cooling time decreases nonlinearly with the linewidth of the cooling transition, and the effect of dark states which may slow down the cooling is considerably reduced. We show that cooling to the ground state is also possible outside the Lamb-Dicke regime. We develop the model and use quantum Monte Carlo calculations for specific examples. We show that a rate equation treatment is a good approximation in all cases.

arXiv:quant-ph/9812014•Physical Review A•May 1, 1999•51 citations

Ground-state laser cooling beyond the Lamb-Dicke limit

Giovanna Morigi, J. I. Cirac, Maciej Lewenstein +1 more

We propose a laser cooling scheme that allows to cool a single atom confined in a harmonic potential to the trap ground state $|0>$. The scheme assumes strong confinement, where the oscillation frequency in the trap is larger than the effective spontaneous decay width, but is not restricted to the Lamb-Dicke limit, i.e. the size of the trap ground state can be larger than the optical wavelength. This cooling scheme may be useful in the context of quantum computations with ions and Bose-Einstein condensation.

arXiv:quant-ph/9706017•Europhysics Letters (EPL)•Jul 1, 1997•42 citations

Laser cooling to a single quantum state in a trap: One-dimensional results

Thomas Pellizzari, P. Marte, P. Zoller

Laser cooling in a trap is investigated for laser and trapping configurations which allow the existence of approximate ``dark states'' of the combined atom-plus-trap system, i.e., states that are decoupled from the laser light by quantum interference. We show that a one-dimensional (1D) free-particle dark state in angular momentum ${\mathit{J}}_{\mathit{g}}$=1 to ${\mathit{J}}_{\mathit{e}}$=1 transitions and in two counterpropagating laser fields survives as an approximate dark state in a ``flat-bottom'' trap of size much larger than the optical wavelength. Furthermore, we show the existence of approximate dark states in 1D harmonic-oscillator potentials. In the latter configuration we are able to provide analytical results.

Physical Review A•Dec 1, 1995•4 citations

Laser cooling a trapped atom in a cavity: Bad-cavity limit

J. I. Cirac, Maciej Lewenstein, P. Zoller

We analyze theoretically a one-dimensional model of laser cooling of an atom or ion trapped in a cavity. We assume that the cavity loss rate is much larger than the atom-cavity coupling (bad-cavity limit) and that the atomic excited state is weakly occupied (low saturation limit). After elimination of the cavity mode and the atomic excited state, we derive rate equations for the populations of the trap states. We find that in the Lamb-Dicke limit the atom can be cooled to the ground state of the trap even in the strong confinement limit. This result is interpreted in terms of quantum interferences between different cooling and heating processes involving spontaneous emission in the cavity.

Physical Review A•Feb 1, 1995•60 citations
We study the laser cooling of one atom in a harmonic trap beyond the Lamb-Dicke regime. By using sequences of laser pulses of different detunings we show that the atom can be confined into just one state of the trap, either the ground state or an excited state of the harmonic potential. The latter can be achieved because under certain conditions an excited state becomes a dark state. We study the problem in one and two dimensions. For the latter case a different cooling mechanism is possible, based on the destructive interference between the effects of laser fields in different directions, which allows the creation of a variety of dark states. For both, one- and two-dimensional cases, Monte Carlo simulations of the cooling dynamics are presented.
We analyze the laser cooling of trapped bosonic gases beyond the Lamb-Dicke limit. We use a quantum master equation formalism to study the cooling dynamics, and show that dark-state cooling methods similar to those previously proposed for a single trapped atom allow for the condensation of a collection of bosons into a single state of the trap, either the ground state or an excited state. Using Monte Carlo simulations we analyze the condensation dynamics for different dimensions, and two different cooling schemes; we also demonstrate the appearance of multistability and hysteresis phenomena.
We study laser cooling of two ions that are trapped in a harmonic potential and interact by Coulomb repulsion. Sideband cooling in the Lamb-Dicke regime is shown to work analogously to sideband cooling of a single ion. Outside the Lamb-Dicke regime, the incommensurable frequencies of the two vibrational modes result in a quasicontinuous energy spectrum that significantly alters the cooling dynamics. The cooling time decreases nonlinearly with the linewidth of the cooling transition, and the effect of dark states which may slow down the cooling is considerably reduced. We show that cooling to the ground state is also possible outside the Lamb-Dicke regime. We develop the model and use quantum Monte Carlo calculations for specific examples. We show that a rate equation treatment is a good approximation in all cases.
We propose a laser cooling scheme that allows to cool a single atom confined in a harmonic potential to the trap ground state ∣0>|0>∣0>. The scheme assumes strong confinement, where the oscillation frequency in the trap is larger than the effective spontaneous decay width, but is not restricted to the Lamb-Dicke limit, i.e. the size of the trap ground state can be larger than the optical wavelength. This cooling scheme may be useful in the context of quantum computations with ions and Bose-Einstein condensation.
Laser cooling in a trap is investigated for laser and trapping configurations which allow the existence of approximate ``dark states'' of the combined atom-plus-trap system, i.e., states that are decoupled from the laser light by quantum interference. We show that a one-dimensional (1D) free-particle dark state in angular momentum Jg{\mathit{J}}_{\mathit{g}}Jg​=1 to Je{\mathit{J}}_{\mathit{e}}Je​=1 transitions and in two counterpropagating laser fields survives as an approximate dark state in a ``flat-bottom'' trap of size much larger than the optical wavelength. Furthermore, we show the existence of approximate dark states in 1D harmonic-oscillator potentials. In the latter configuration we are able to provide analytical results.
We analyze theoretically a one-dimensional model of laser cooling of an atom or ion trapped in a cavity. We assume that the cavity loss rate is much larger than the atom-cavity coupling (bad-cavity limit) and that the atomic excited state is weakly occupied (low saturation limit). After elimination of the cavity mode and the atomic excited state, we derive rate equations for the populations of the trap states. We find that in the Lamb-Dicke limit the atom can be cooled to the ground state of the trap even in the strong confinement limit. This result is interpreted in terms of quantum interferences between different cooling and heating processes involving spontaneous emission in the cavity.