Time crystal in a static cavity QED Hamiltonian

Peter F. Herskind, Aurélien Dantan, Joan P. Marler +2 more

Cavity QED experimental results demonstrating collective strong coupling between ensembles of atomic ions cooled into Coulomb crystals and optical cavity fields have been achieved. Collective Zeeman coherence times of milliseconds have furthermore been obtained.

Jan Dereziński, Christian Gérard

Jonathan Simon

Haozhen Li, Zerong Li, Ran Zeng +6 more

The dynamical control of single-photon scattering in a one-dimensional waveguide coupled to a Floquet atom-cavity system with time-modulated coupling constants is investigated. The analytical expressions for determining the scattering properties are obtained by using an effective Floquet Hamiltonian in real space. The photon transport is extremely sensitive to the time-modulated atom-cavity coupling strengths. Two cases, i.e., the effective Floquet Hamiltonian either includes or excludes a static coupling term, are discussed in detail. The results show that, with such Floquet atom-cavity configuration, an active photonic switch with nearly ideal switching contrast could be implemented. The transmission of the waveguide photons with different frequencies can dynamically be switched on or off via adjusting the modulated amplitude or relative modulated phase no matter whether the static coupling between the atom and the two cavity modes is considered or not. The application of the dynamic modulated atom-cavity coupling strengths instead of a purely static one makes our photonic switch more tunable. These results are expected to be applicable in quantum information processing and in active quantum device design involving dynamical modulation.

Pascal Degiovanni, Valentin Bonzom, Hichem Bouzidi +4 more

Peter F. Herskind, A. Mortensen, Jens Lykke Sørensen +1 more

We present a proposal for using ion Coulomb crystals in cavity QED experiments. Due to the high degree of spatial confinement of ions in Coulomb crystals, such ion ensembles will have some advantages over systems based on neutral atoms. Simulations of a system with up to 3200 ions coupled to a standing wave cavity with a finesse of about 4000 is presented, and show that our setup can be used for experiments within the strongly coupled regime of cavity QED. Furthermore, the potential of the system as a quantum memory device for light, is considered.