3D dissipative motion of atoms in a strongly coupled driven cavity

Andrew C. Doherty, A. S. Parkins, S. M. Tan +1 more

We investigate the quantum-mechanical state of motion of an atom strongly coupled to an optical cavity. The atomic motion is coupled to the environment through cavity decay and this leads to nonclassical effects due to the dissipative evolution. The scheme is examined as an atomic position measurement and the symmetry of the cavity field mode is found to lead to Schr\"odinger cat states of the motion in the selective evolution.

Christoph Maschler, Helmut Ritsch

Craig M. Savage

Recently there has been both theoretical [1-3] and experimental [4] interest in atoms strongly coupled to single mode optical cavities. Strong coupling means that the energy level splitting due to a single quantum of excitation is comparable to the dissipative linewidth of the system. Single quantum frequency splitting has been observed for as few as 20 atoms strongly coupled to a cavity [4].

A. Vidiella-Barranco, José Antonio Roversi, H. M. Moya-Cessa

Péter Horák, Helmut Ritsch

We extend an earlier semiclassical model to describe the dissipative motion of N atoms coupled to M modes inside a coherently driven high-finesse cavity. The description includes momentum diffusion via spontaneous emission and cavity decay. Simple analytical formulas for the steady-state temperature and the cooling-time for a single atom are derived and show surprisingly good agreement with direct stochastic simulations of the semiclassical equations for N atoms with properly scaled parameters. A thorough comparison with standard free-space Doppler cooling is performed and yields a lower temperature and a cooling-time enhancement by a factor of M times the square of the ratio of the atom-field coupling constant to the cavity decay rate. Finally, it is shown that laser cooling with negligible spontaneous emission should indeed be possible, especially for relatively light particles in a strongly coupled field configuration.

Dan Stamper-Kurn