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

Cavity-mediated collective laser-cooling of an atomic gas inside an asymmetric trap

Олег Ким, Prasenjit Deb, Almut Beige

Published Jun 9, 2015• 2 citations
OpenAlex

Abstract

In this paper, we identify a quantum coherence with the ability to induce collective dynamics in an atomic gas, when a cooling laser is applied. When present, the mean phonon number per particle changes at a rate, which is proportional to the total number of particles in the system. We then propose to use this effect to cool atoms in a cyclic two-stage process to very low temperatures. During each displacement stage, the atoms move freely inside an asymmetric trapping potential, thereby accumulating away from its centre. During each cooling stage, a cooling laser is applied, which returns the atoms to the centre of the trap, while decreasing their mean phonon number. Alternating both stages is shown to transfer the atoms to a final temperature, which vanishes in the infinitely-many particle limit.

Related papers

Cavity-mediated collective laser-cooling of a non-interacting atomic gas inside an asymmetric trap to very low temperatures

Oleg Kim, Prasenjit Deb, Almut Beige

In this paper, we identify a many-particle phonon expectation value ζ with the ability to induce collective dynamics in a non-interacting atomic gas inside an optical cavity. We then propose to utilise this expectation value to enhance the laser cooling of many atoms through a cyclic two-stage process which consists of cooling and displacement stages. During cooling stages, short laser pulses are applied. These use ζ as a resource and decrease the vibrational energy of the atomic gas by a fixed amount. Subsequent displacement stages use the asymmetry of the trapping potential to replenish the many-particle phonon expectation value ζ. Alternating both stages of the cooling process is shown to transfer the atomic gas to a final temperature which vanishes in the infinitely-many particle limit.

arXiv:1506.02910•Journal of Modern Optics•Mar 7, 2018•7 citations

Cooling many particles at once

Almut Beige, P. L. Knight, Giuseppe Vitiello

We propose a mechanism for the collective cooling of a large number N of trapped particles to very low temperatures by applying red-detuned laser fields and coupling them to the quantized field inside an optical resonator. The dynamics is described by what appears to be rate equations, but where some of the major quantities are coherences and not populations. The cooperative behaviour of the system provides cooling rates of the same order of magnitude as the cavity decay rate κ. This constitutes a significant speed-up compared to other cooling mechanisms since κ can, in principle, be as large as times the single-particle cavity or laser coupling constant.

arXiv:quant-ph/0404160•New Journal of Physics•Apr 14, 2005•42 citations

A quantum approach to cavity mediated laser cooling

Tony Blake

Cavity-mediated cooling has the potential to become one of the most efficient techniques to cool molecular species down to very low temperatures. This thesis studies the use of rate equations to analyse the cooling process in such systems. In particular the master equation is used to find rate equations that can determine the rate of change of phonons in the system. The general idea behind cavity cooling is the continuous conversion of phonons into cavity photons. While there is no spontaneous emission and decay rate associated with the concept of phonons, photons are created after a change in the phonon number has occurred and can then leak out through the cavity mirrors easily. Hence the conversion of phonons into photons can result in the constant removal of phonon energy from the system. In this thesis we compare cavity mediated cooling with single particle laser cooling. It is shown that cavity cooling is essentially the same as ordinary laser cooling. This is done by calculating the stationary state phonon number mss and the cooling rate y as a function of the system parameters. For example, when the trap phonon frequency υ is either much larger or much smaller than the cavity decay rate k , the minimum stationary state phonon number scales as k²/16v² (strong confinement regime) and as k/4 (weak confinement regime), respectively. Replacing k with Ѓ yields the steady states associated with ordinary laser cooling.

•Sep 1, 2011•0 citations

Stochastic laser cooling enabled by many-body effects

Roie Dann, Ronnie Kosloff

Abstract A novel laser cooling mechanism based on many-body effects is presented. The method can be applied to the cooling of a large class of atoms and molecules at a higher density than commonly excepted by existing methods. The cooling mechanism relies on the collective encounter of particles and light. Stochastic events between the particles and photons, as well as a collective effect, give rise to energy transfer between these media. Such a mechanism relies on multiple light–matter encounters, therefore requiring a sufficient particle density, ρ ∼ 10 14 cm −3 . This is an advantage for experiments where a high phase space density is required. A second tuning laser can be added, increasing the applicability to many types of atoms and molecules. This tuning laser changes the inter-particle potential by inducing an AC Stark effect. As a result, the required trapping density can be reduced to ρ ∼ 10 6 cm −3 . Simulations of phase space distributions were performed, comparing different particle densities, trap potentials and light field intensity profiles. The modelling shows efficient cooling rates up to 10 2 K s −1 for a dense ensemble of 87 Rb atoms, and cooling rates of up to 6 · 10 2 K s −1 when adding an additional tuning source.

arXiv:1612.04294•Journal of Physics B Atomic Molecular and Optical Physics•May 10, 2018•2 citations

Collectively enhanced quantum light-matter interactions

Олег Ким

In this thesis, we investigate dynamics of many-body atomic systems coupled to electromagnetic fields. We find that collective effects present in cavity-mediated laser cooling and high temperatures of bubble in sonoluminescence can be explained using a two-stage model which combines quantum-optical models and thermodynamical processes. We show how the collective processes are strongly dependent on mutual atomic coherences and how these coherences need to be recreated for the continous collective processes to take place. The model mechanism behind both cavity-mediated laser cooling and sonoluminescence heating is alternating periods of thermalisation with cooling or heating cycles. The thermalisation stage is characterised by relatively weak interactions between the atomic system and its environment, while allowing the system to thermalise and to create phonon and electronic coherences necessary for the next stage. The second stage, when cooling or heating occurs, marks strong interactions of the atomic system with the surrounding radiation field, which renders interactions between the particles negligible. During this stage, the atomic coherences created earlier fuel the cooling or heating process, allowing the system to reach a more beneficial stationary state. For cavity-mediated laser cooling of an atomic gas, we show that dispersing cooling pulses with periods of thermalisation in an asymmetric potential can result in very low temperatures of the atomic gas. By applying this to atomic interactions of sonoluminescence, we can describe different parts of the lifecycle of the cavitating bubble and how very high temperatures arise inside of it.

•Jun 1, 2015•0 citations

Optomechanical Cavity Cooling of an Atomic Ensemble

Monika Schleier-Smith, Ian D. Leroux, Hao Zhang +2 more

We demonstrate cavity sideband cooling of a single collective motional mode of an atomic ensemble down to a mean phonon occupation number ⟨n⟩(min⁡)=2.0(-0.3)(+0.9). Both ⟨n⟩(min) and the observed cooling rate are in good agreement with an optomechanical model. The cooling rate constant is proportional to the total photon scattering rate by the ensemble, demonstrating the cooperative character of the light-emission-induced cooling process. We deduce fundamental limits to cavity cooling either the collective mode or, sympathetically, the single-atom degrees of freedom.

arXiv:1104.4623•Physical Review Letters•Sep 28, 2011•105 citations
In this paper, we identify a quantum coherence with the ability to induce collective dynamics in an atomic gas, when a cooling laser is applied. When present, the mean phonon number per particle changes at a rate, which is proportional to the total number of particles in the system. We then propose to use this effect to cool atoms in a cyclic two-stage process to very low temperatures. During each displacement stage, the atoms move freely inside an asymmetric trapping potential, thereby accumulating away from its centre. During each cooling stage, a cooling laser is applied, which returns the atoms to the centre of the trap, while decreasing their mean phonon number. Alternating both stages is shown to transfer the atoms to a final temperature, which vanishes in the infinitely-many particle limit.
In this paper, we identify a many-particle phonon expectation value ζ with the ability to induce collective dynamics in a non-interacting atomic gas inside an optical cavity. We then propose to utilise this expectation value to enhance the laser cooling of many atoms through a cyclic two-stage process which consists of cooling and displacement stages. During cooling stages, short laser pulses are applied. These use ζ as a resource and decrease the vibrational energy of the atomic gas by a fixed amount. Subsequent displacement stages use the asymmetry of the trapping potential to replenish the many-particle phonon expectation value ζ. Alternating both stages of the cooling process is shown to transfer the atomic gas to a final temperature which vanishes in the infinitely-many particle limit.
We propose a mechanism for the collective cooling of a large number N of trapped particles to very low temperatures by applying red-detuned laser fields and coupling them to the quantized field inside an optical resonator. The dynamics is described by what appears to be rate equations, but where some of the major quantities are coherences and not populations. The cooperative behaviour of the system provides cooling rates of the same order of magnitude as the cavity decay rate κ. This constitutes a significant speed-up compared to other cooling mechanisms since κ can, in principle, be as large as times the single-particle cavity or laser coupling constant.
Cavity-mediated cooling has the potential to become one of the most efficient techniques to cool molecular species down to very low temperatures. This thesis studies the use of rate equations to analyse the cooling process in such systems. In particular the master equation is used to find rate equations that can determine the rate of change of phonons in the system. The general idea behind cavity cooling is the continuous conversion of phonons into cavity photons. While there is no spontaneous emission and decay rate associated with the concept of phonons, photons are created after a change in the phonon number has occurred and can then leak out through the cavity mirrors easily. Hence the conversion of phonons into photons can result in the constant removal of phonon energy from the system. In this thesis we compare cavity mediated cooling with single particle laser cooling. It is shown that cavity cooling is essentially the same as ordinary laser cooling. This is done by calculating the stationary state phonon number mss and the cooling rate y as a function of the system parameters. For example, when the trap phonon frequency υ is either much larger or much smaller than the cavity decay rate k , the minimum stationary state phonon number scales as k²/16v² (strong confinement regime) and as k/4 (weak confinement regime), respectively. Replacing k with Ѓ yields the steady states associated with ordinary laser cooling.
Abstract A novel laser cooling mechanism based on many-body effects is presented. The method can be applied to the cooling of a large class of atoms and molecules at a higher density than commonly excepted by existing methods. The cooling mechanism relies on the collective encounter of particles and light. Stochastic events between the particles and photons, as well as a collective effect, give rise to energy transfer between these media. Such a mechanism relies on multiple light–matter encounters, therefore requiring a sufficient particle density, ρ ∼ 10 14 cm −3 . This is an advantage for experiments where a high phase space density is required. A second tuning laser can be added, increasing the applicability to many types of atoms and molecules. This tuning laser changes the inter-particle potential by inducing an AC Stark effect. As a result, the required trapping density can be reduced to ρ ∼ 10 6 cm −3 . Simulations of phase space distributions were performed, comparing different particle densities, trap potentials and light field intensity profiles. The modelling shows efficient cooling rates up to 10 2 K s −1 for a dense ensemble of 87 Rb atoms, and cooling rates of up to 6 · 10 2 K s −1 when adding an additional tuning source.
In this thesis, we investigate dynamics of many-body atomic systems coupled to electromagnetic fields. We find that collective effects present in cavity-mediated laser cooling and high temperatures of bubble in sonoluminescence can be explained using a two-stage model which combines quantum-optical models and thermodynamical processes. We show how the collective processes are strongly dependent on mutual atomic coherences and how these coherences need to be recreated for the continous collective processes to take place. The model mechanism behind both cavity-mediated laser cooling and sonoluminescence heating is alternating periods of thermalisation with cooling or heating cycles. The thermalisation stage is characterised by relatively weak interactions between the atomic system and its environment, while allowing the system to thermalise and to create phonon and electronic coherences necessary for the next stage. The second stage, when cooling or heating occurs, marks strong interactions of the atomic system with the surrounding radiation field, which renders interactions between the particles negligible. During this stage, the atomic coherences created earlier fuel the cooling or heating process, allowing the system to reach a more beneficial stationary state. For cavity-mediated laser cooling of an atomic gas, we show that dispersing cooling pulses with periods of thermalisation in an asymmetric potential can result in very low temperatures of the atomic gas. By applying this to atomic interactions of sonoluminescence, we can describe different parts of the lifecycle of the cavitating bubble and how very high temperatures arise inside of it.
We demonstrate cavity sideband cooling of a single collective motional mode of an atomic ensemble down to a mean phonon occupation number ⟨n⟩(min⁡)=2.0(-0.3)(+0.9). Both ⟨n⟩(min) and the observed cooling rate are in good agreement with an optomechanical model. The cooling rate constant is proportional to the total photon scattering rate by the ensemble, demonstrating the cooperative character of the light-emission-induced cooling process. We deduce fundamental limits to cavity cooling either the collective mode or, sympathetically, the single-atom degrees of freedom.