Many-atom–cavity QED system with homogeneous atom–cavity coupling

Abstract

We demonstrate a many-atom-cavity system with a high-finesse dual-wavelength standing wave cavity in which all participating rubidium atoms are nearly identically coupled to a 780-nm cavity mode. This homogeneous coupling is enforced by a one-dimensional optical lattice formed by the field of a 1560-nm cavity mode. OCIS codes:(020.0020) Atomic and molecular physics, (120.3940) Metrology, (140.4780) Optical resonators, (300.6260) Spectroscopy, diode lasersThere has been growing interest in collective interactions of large ensembles of atoms with cavity fields, in addition to experiments [1, 2] pursuing cavity quantum electrodynamics (cQED) with individual atoms. Topics studied include cavity-aided entanglement generation (spin squeezing) for quantum-enhanced metrology [3][4][5]; opto-mechanics with atoms, where collective motional degrees of freedom are coupled to cavity fields [6,7]; cavity-enhanced atomic quantum memories for quantum information processing [8]; and ultra-narrow-linewidth lasers using narrow-transition ultra-cold atoms as the gain medium for metrological purposes [9,10]. Important in many such systems is the inhomogeneity in the coupling strength between the participating atoms and the cavity field, which degrades the coherence of the interactions and complicates the dynamics and the analysis of the basic physics by obscuring the relevant system parameters. [11].Limiting our attention to Fabry-Pérot type cavities, in which the modes are standing waves, homogeneous coupling of atoms to the relevant cavity field (the probe mode) can be achieved by tightly trapping the atoms with a spatial period that is commensurate with the wavelength of the probe. Thus far, experimentally realized trapping configurations have involved incommensurate trap-probe periods, resulting in inhomogeneous atom-probe couplings that often require the definition of effective, averaged coupling constants [7]. Two recent efforts came to our attention that investigate commensurate dual-wavelength cavity designs; one utilizes a traveling-wave cavity to trap and probe atoms in which there is no particular atom registration [12], and the other utilizes a standing wave cavity, for the different purpose of investigating atomic self organization [13].

Spatially homogeneous entanglement for matter-wave interferometry created with time-averaged measurements

“…Another appealing approach is to introduce a commensurate lattice [3,17]. This approach requires special mirror coatings and frequency doubling equipment and doesn't permit guided movement for atom interferometry within the cavity mode.…”

Quantum phase magnification

“…However, these effects are negligible in the parameter range we use for the magnification protocol and can be ignored (23). The details of the experimental apparatus are described in (12,25). We load up to 5 × 10 5 atoms at 25 mK into an optical lattice inside the highfinesse (1.75 × 10 5 ) cavity (23).…”

One- and two-axis squeezing of atomic ensembles in optical cavities

“…The twisting schemes can be implemented with 87 Rb atoms trapped in an optical lattice, as demonstrated in [13,19,21,41]. One option is to realize the ground states on the hyperfine clock transition = = ñ« |F m 1, 0…”