368 research outputs found
Spin waves and Collisional Frequency Shifts of a Trapped-Atom Clock
We excite spin-waves with spatially inhomogeneous pulses and study the
resulting frequency shifts of a chip-scale atomic clock of trapped Rb.
The density-dependent frequency shifts of the hyperfine transition simulate the
s-wave collisional frequency shifts of fermions, including those of optical
lattice clocks. As the spin polarizations oscillate in the trap, the frequency
shift reverses and it depends on the area of the second Ramsey pulse,
exhibiting a predicted beyond mean-field frequency shift. Numerical and
analytic models illustrate the observed behaviors.Comment: Will appear soon in Physical Review Letters - Typos correcte
Fiber Fabry-Perot cavity with high finesse
We have realized a fiber-based Fabry-Perot cavity with CO2 laser-machined
mirrors. It combines very small size, high finesse F>=130000, small waist and
mode volume, and good mode matching between the fiber and cavity modes. This
combination of features is a major advance for cavity quantum electrodynamics
(CQED), as shown in recent CQED experiments with Bose-Einstein condensates
enabled by this cavity [Y. Colombe et al., Nature 450, 272 (2007)]. It should
also be suitable for a wide range of other applications, including coupling to
solid-state emitters, gas detection at the single-particle level, fiber-coupled
single-photon sources and high-resolution optical filters with large stopband.Comment: Submitted to New J. Phys
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