Cavity QED based on room temperature atoms interacting with a photonic crystal cavity: a feasibility study

Abstract

The paradigm of cavity QED is a two-level emitter interacting with a high quality factor single mode optical resonator. The hybridization of the emitter and photon wave functions mandates large vacuum Rabi frequencies and long coherence times; features that so far have been successfully realized with trapped cold atoms and ions and localized solid state quantum emitters such as superconducting circuits, quantum dots, and color centers 1,2 . Thermal atoms on the other hand, provide us with a dense emitter ensemble and in comparison to the cold systems are more compatible with integration, hence enabling large-scale quantum systems. However, their thermal motion and large transit time broadening is a major challenge that has to be circumvented. A promising remedy could benefit from the highly controllable and tunable electromagnetic fields of a nano-photonic cavity with strong local electric-field enhancements. Utilizing this feature, here we calculate the interaction between fast moving, thermal atoms and a nano-beam photonic crystal cavity (PCC) with large quality factor and small mode volume. Through fully quantum mechanical calculations, including Casimir-Polder potential (i.e. the effect of the surface on radiation properties of an atom) we show, when designed properly, the achievable coupling between the flying atom and the cavity photon would be strong enough to lead to Rabi flopping in spite of short interaction times. In addition, the time-resolved detection of different trajectories can be used to identify single and multiple atom counts. This probabilistic approach will find applications in cavity QED studies in dense atomic media and paves the way towards realizing coherent quantum control schemes in large-scale macroscopic systems aimed at out of the lab quantum devices.

Large cooperativity in strongly coupled chip-scale photonic-atomic integrated system

“…Which might allow to study strong coupling interactions of only few atoms in a compact and a robust on-chip platform. The work presented here opens the possibility to utilize hot atoms for applications in the quantum domain such as magnetometry 55 or Rydberg electrometry 56 and especially in the CQED 57 field.…”

Elongated-Hexagonal Photonic Crystal for Buffering, Sensing, and Modulation

“…Optical buffer is a significant component for all-optical communication networks, processors, and optical computers in the future. The unique PCW nanostructure designed is efficient for optical buffering performances [ 3 , 8 ] because of room-temperature operation [ 9 ], masterful manipulation of the guided-mode dispersion relations with a change in subtle structure parameters, and compatibility for on-chip integration [ 10 ].…”

Super-extended nanofiber-guided field for coherent interaction with hot atoms

“…Light-matter interaction can be enhanced by a tight optical mode volume and by a collective coupling of this mode to an ensemble of atoms. While reduced mode volumes are achieved in small optical cavities [5] or with tightly focused beams in free space [6,7], they are typically incompatible with large ensembles of atoms due to the associated short Rayleigh range z R .…”