1,909 research outputs found
2000-times repeated imaging of strontium atoms in clock-magic tweezer arrays
We demonstrate single-atom resolved imaging with a survival probability of
and a fidelity of , enabling us to perform repeated
high-fidelity imaging of single atoms in tweezers for thousands of times. We
further observe lifetimes under laser cooling of more than seven minutes, an
order of magnitude longer than in previous tweezer studies. Experiments are
performed with strontium atoms in tweezer arrays, which is at
a magic wavelength for the clock transition. Tuning to this wavelength is
enabled by off-magic Sisyphus cooling on the intercombination line, which lets
us choose the tweezer wavelength almost arbitrarily. We find that a single not
retro-reflected cooling beam in the radial direction is sufficient for
mitigating recoil heating during imaging. Moreover, this cooling technique
yields temperatures below K, as measured by release and recapture.
Finally, we demonstrate clock-state resolved detection with average survival
probability of and average state detection fidelity of .
Our work paves the way for atom-by-atom assembly of large defect-free arrays of
alkaline-earth atoms, in which repeated interrogation of the clock transition
is an imminent possibility.Comment: 6 pages, 5 figures, 1 vide
Alkaline earth atoms in optical tweezers
We demonstrate single-shot imaging and narrow-line cooling of individual
alkaline earth atoms in optical tweezers; specifically, strontium-88 atoms
trapped in light. We achieve high-fidelity
single-atom-resolved imaging by detecting photons from the broad singlet
transition while cooling on the narrow intercombination line, and extend this
technique to highly uniform two-dimensional arrays of tweezers. Cooling
during imaging is based on a previously unobserved narrow-line Sisyphus
mechanism, which we predict to be applicable in a wide variety of experimental
situations. Further, we demonstrate optically resolved sideband cooling of a
single atom close to the motional ground state of a tweezer. Precise
determination of losses during imaging indicate that the branching ratio from
P to D is more than a factor of two larger than commonly
quoted, a discrepancy also predicted by our ab initio calculations. We also
measure the differential polarizability of the intercombination line in a
tweezer and achieve a magic-trapping configuration by tuning
the tweezer polarization from linear to elliptical. We present calculations, in
agreement with our results, which predict a magic crossing for linear
polarization at and a crossing independent of polarization
at 500.65(50)nm. Our results pave the way for a wide range of novel
experimental avenues based on individually controlled alkaline earth atoms in
tweezers -- from fundamental experiments in atomic physics to quantum
computing, simulation, and metrology implementations
Quantum networks with neutral atom processing nodes
Quantum networks providing shared entanglement over a mesh of quantum nodes
will revolutionize the field of quantum information science by offering novel
applications in quantum computation, enhanced precision in networks of sensors
and clocks, and efficient quantum communication over large distances. Recent
experimental progress with individual neutral atoms demonstrates a high
potential for implementing the crucial components of such networks. We
highlight latest developments and near-term prospects on how arrays of
individually controlled neutral atoms are suited for both efficient remote
entanglement generation and large-scale quantum information processing, thereby
providing the necessary features for sharing high-fidelity and error-corrected
multi-qubit entangled states between the nodes. We describe both the
functionality requirements and several examples for advanced, large-scale
quantum networks composed of neutral atom processing nodes.Comment: 10 pages, 5 figure
High Resolution Near-Infrared Spectroscopy of FUors and FUor-like stars
We present new high resolution (R=18,000) near-infrared spectroscopic
observations of a sample of classical FU Orionis stars (FUors) and other young
stars with FUor characteristics that are sources of Herbig-Haro flows. Spectra
are presented for the region 2.203 - 2.236 microns which is rich in absorption
lines sensitive to both effective temperatures and surface gravities of stars.
Both FUors and FUor-like stars show numerous broad and weak unidentified
spectral features in this region. Spectra of the 2.280 - 2.300 micron region
are also presented, with the 2.2935 micron v=2-0 CO absorption bandhead being
clearly the strongest feature seen in the spectra all FUors and Fuor-like
stars. A cross-correlation analysis shows that FUor and FUor-like spectra in
the 2.203 - 2.236 micron region are not consistent with late-type dwarfs,
giants, nor embedded protostars. The cross-correlations also show that the
observed FUor-like Herbig-Haro energy sources have spectra that are
substantively similar to those of FUors. Both object groups also have similar
near-infrared colors. The large line widths and double-peaked nature of the
spectra of the FUor-like stars are consistent with the established accretion
disk model for FUors, also consistent with their near-infrared colors. It
appears that young stars with FUor-like characteristics may be more common than
projected from the relatively few known classical FUors.Comment: 21 pages, 4 figures, accepted by The Astronomical Journa
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