Statistical uncertainty of 2.5× 10− 16 for the 199 Hg 1 S 0− 3 P 0 clock transition against a primary frequency standard (original) (raw)
Related papers
We report on the Lamb-Dicke spectroscopy of the doubly forbidden ð6s 2 Þ 1 S 0 $ ð6s6pÞ 3 P 0 transition in 199 Hg atoms confined to a vertical 1D optical lattice. With lattice trapping of & 10 3 atoms and a 265.6 nm probe laser linked to the LNE-SYRTE primary frequency reference we have determined the center frequency of the transition for a range of lattice wavelengths and at two lattice trap depths. We find the Stark-free (magic) wavelength to be 362.53(0.21) nm-essential knowledge for future use of this line in a clock with anticipated 10 À18 range accuracy. We also present evidence of the laser excitation of a Wannier-Stark ladder of states in a lattice of well depth 10E R .
Neutral Atom Frequency Reference in the Deep Ultraviolet with Fractional Uncertainty=5.7×10^{-15}
Physical Review Letters, 2012
A neutral atom frequency reference in the deep UV with 10 −15 range uncertainty We present an assessment of the (6s 2 ) 1 S0 ↔ (6s7s) 3 P0 clock transition frequency in 199 Hg with an uncertainty reduction of nearly three orders of magnitude and demonstrate an atomic quality factor, Q, of ∼10 14 . The 199 Hg atoms are confined in a vertical lattice trap with light at the newly determined magic wavelength of 362.5697±0.0011 nm and at a lattice depth of 20 ER. The atoms are loaded from a single stage magneto-optical trap with cooling light at 253.7 nm. The high Q factor is obtained with an 80 ms Rabi pulse at 265.6 nm. The frequency of the clock transition is found to be 1 128 575 290 808 162.0 ± 6.4 (sys.) ± 0.3 (stat.) Hz (fractional uncertainty = 5.7×10 −15 ). Neither an atom number nor second order Zeeman dependence have yet to be detected. Only three laser wavelengths are used for the cooling, lattice trapping, probing and detection.
Metrologia
We measured the absolute frequency of the optical clock transition 1S0 (F = 1/2) - 3P0 (F = 1/2) of 171Yb atoms confined in a one-dimensional optical lattice and it was determined to be 518 295 836 590 863.5(8.1) Hz. The frequency was measured against Terrestrial Time (TT; the SI second on the geoid) by using an optical frequency comb of which the frequency was phase-locked to an H-maser as a flywheel oscillator traceable to TT. The magic wavelength was also measured as 394 798.48(79) GHz. The results are in good agreement with two previous measurements of other institutes within the specified uncertainty of this work.
Mercury Optical Lattice Clock: From High-Resolution Spectroscopy to Frequency Ratio Measurements
2017
This thesis presents the development of a high-accuracy optical frequency standard based on neutral mercury 199Hg trapped in an optical lattice. We will present the experimental setup and the improvements that were made during this thesis, which have allowed us to perform spectroscopy on the doubly forbidden 1S0 → 3P0 mercury clock transition at the Hz level resolution. With such a resolution, we have been able to perform an in-depth study of the physical effects affecting the clock transition.This study represents a factor 60 improvement in accuracy on the knowledge of the clock transition frequency, pushing the accuracy below the current realization of the SI second by the best cesium atomic fountains. Finally, we will present the results of several comparison campaigns between the mercury clock and other state-of the-art frequency standards, both in the optical and in the microwave domain.
Physical Review Letters, 2006
We develop a method of spectroscopy that uses a weak static magnetic field to enable direct optical excitation of forbidden electric-dipole transitions that are otherwise prohibitively weak. The power of this scheme is demonstrated using the important application of optical atomic clocks based on neutral atoms confined to an optical lattice. The simple experimental implementation of this method-a single clock laser combined with a dc magnetic field-relaxes stringent requirements in current lattice-based clocks (e.g., magnetic field shielding and light polarization), and could therefore expedite the realization of the extraordinary performance level predicted for these clocks. We estimate that a clock using alkaline-earthlike atoms such as Yb could achieve a fractional frequency uncertainty of well below 10 ÿ17 for the metrologically preferred even isotopes.
Clock transition for a future optical frequency standard with trapped atoms
Physical Review A, 2003
We report the first direct excitation of the strongly forbidden 5s 2 1 S0 −5s5p 3 P0 transition in 87 Sr. Its frequency is 429 228 004 235 (20) kHz. A resonant laser creates a small leak in a magneto-optical trap (MOT): atoms build up to the metastable 3 P0 state and escape the trapping process, leading to a detectable decrease in the MOT fluorescence. This line has a natural width of 10 −3 Hz and can be used for a new generation of optical frequency standards using atoms trapped in a light shift free dipole trap.
Testing the Stability of Fundamental Constants with the Hg+199 Single-Ion Optical Clock
Physical Review Letters, 2003
Over a two-year duration, we have compared the frequency of the 199 Hg + 5d 10 6s 2 S 1/2 (F = 0) ←→ 5d 9 6s 2 2 D 5/2 (F = 2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133 Cs. These measurements show that any fractional time variation of the ratio νCs/νHg between the two frequencies is smaller than ±7 × 10 −15 yr −1 (1σ uncertainty). According to recent atomic structure calculations, this sets an upper limit to a possible fractional time variation of gCs(me/mp)α 6.0 at the same level.
Precision measurement of the forbidden 21S0 – 23S1 transition frequency in a helium atom
Quantum Electronics
We demonstrate the possibility of measuring the forbidden 2 1 S 0-2 3 S 1 transition frequency (l = 1557 nm) of a helium atom by the method of stimulated Raman scattering through the intermediate 2 3 P 1 level. Singlet (2 1 S 0) and triplet (2 3 S 1) states have long lifetimes of 20 ms and 8000 s, respectively. The transition is important for the spectroscopy of the helium atom because it relates the singlet and triplet parts of the spectrum.
Absolute frequency measurement of the 40Ca+ 4s(2)S_(1/2)-3d(2)D_(5/2) clock transition
Physical review letters, 2009
We report on the first absolute transition frequency measurement at the 10;{-15} level with a single, laser-cooled 40Ca+ ion in a linear Paul trap. For this measurement, a frequency comb is referenced to the transportable Cs atomic fountain clock of LNE-SYRTE and is used to measure the 40Ca+ 4s ;{2}S_{1/2}-3d ;{2}D_{5/2} electric-quadrupole transition frequency. After the correction of systematic shifts, the clock transition frequency nu_{Ca;{+}}=411 042 129 776 393.2(1.0) Hz is obtained, which corresponds to a fractional uncertainty within a factor of 3 of the Cs standard. In addition, we determine the Landé g factor of the 3d;{2}D_{5/2} level to be g_{5/2}=1.200 334 0(3).