COLDCATC · Collective dynamics of cold atoms in a cavity
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2004-02-01 → 2005-01-31
- EU contribution
- €39,175
- Participants
- 1
- Scheme
- EIF
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Results in brief
Final Activity Report Summary - COLDCATC (Collective dynamics of cold atoms in a cavity)
We studied various aspects of the mechanical effect of light on atoms in an optical resonator where the interaction is significantly enhanced due to the photon "recycling'' by mirror reflections. The atom, meanwhile moving under the influence of the cavity field force, exerts a non-negligible backaction on the field. We have set up a numerical simulation, based on the quantum Monte Carlo wavefunction method, which describes the coupled, nonlinear dynamics of the atomic centre-of-mass and the field modes at a fully quantum mechanical level. We proved that the far-off-resonance dipole trap created by a cavity field actively damps the atomic vibration despite the large detuning. As a consequence, it captures atoms with much larger initial velocities and traps them much longer than external dipole traps. Many-body effects are an inherent feature of the cavity-induced forces for a dilute gas of atoms. In certain schemes the efficiency of the cooling significantly improves owing to a collective action of the atoms, e.g., they can self-organise into a regular pattern and dissipate motional energy by superradiant scattering into the cavity. We determined the conditions for the self-organisation, a first-order symmetry-breaking phase transition, to occur.
Data: CORDIS, © European Union
Project objective
Cavity cooling is an efficient method for the cooling of atoms and molecules. In general it can be applied on an arbitrary particle with induced dipole moment. The friction mechanism relies on the strongly coupled, non-linear dynamics of the atomic centre-of-mass motion and the radiation field contained in a high-finesse optical resonator. The project objective is to study new effects in the three-dimensional, dissipative motion of atoms in a cavity, that are:1.The combination of the cooling and trapping dynamics with an interference effect that occurs when both components of the coupled atom-cavity system are simultaneously pumped;2.The cavity-mediated atom-atom correlation that underlies the dramatic many-body effects in a dilute gas of atoms, and its possible role in the enhancement of the formation of molecules by photo-association of atom pairs;3.The self-organization of driven atoms into a regular pattern, which is accompanied by a collective cooling and super radiant light scattering into the cavity, in the large atom number limit (above 10000 atoms);4.The quintile motion of atoms in the cavity field to describe the dissipative dynamics of a Base-Einstein condensate as well as the possible entanglement resulting from the correlated motion of remote atoms in the cavity. The theoretical approach is based on an effective master equation that we solve in the semi classical limit by powerful phase-space methods. Using a truncated Wagner function expansion, we derived coupled stochastic Ito equations, and their numerical integration yields random trajectories in phase space. Physical quantities can be extracted by ensemble averaging over many runs. The quantum motion can be treated using the Quantum Monte Carlo Wave function method to solve the same effective master equation.
Original text from CORDIS.
Participants
- SZILARTESTFIZIKAI ES OPTIKAI KUTATOINTEZET - MAGYAR TUDOMANYOS AKADEMIA · BUDAPESTCoordinatorCity levelHungary
Links
Data: CORDIS, © European Union