Precision Measurement Based on Ultracold Atoms and Cold Molecules
- JILA, National Institute of Standards and Technology, Boulder, CO 80309-0440 (United States)
Ultracold atoms and molecules provide ideal stages for precision tests of fundamental physics. With microkelvin neutral strontium atoms confined in an optical lattice, we have achieved a fractional resolution of 4 x 10-15 on the 1S0 - 3P0 doubly-forbidden 87Sr clock transition at 698 nm. The overall systematic uncertainty of the clock is evaluated below the 10-15 level. The ultrahigh spectral resolution permits resolving the nuclear spin states of the clock transition at small magnetic fields, leading to measurements of the 3P0 magnetic moment and metastable lifetime. In addition, photoassociation spectroscopy performed on the narrow 1S0 - 3P1 transition of 88Sr shows promise for efficient optical tuning of the ground state scattering length and production of ultracold ground-state molecules. Lattice-confined Sr2 molecules are suitable for constraining the time-variation of electron-proton mass ratio. In a separate experiment, cold, ground state polar molecules produced from Stark decelerators have enabled an order of magnitude improvement in measurement precision of ground-state, {lambda}-doublet microwave transitions in the OH molecule. Comparing the laboratory results to those from OH megamasers in interstellar space will allow a sensitivity of 10-6 for measuring the potential time variation of the fundamental fine structure constant {delta}{alpha}/{alpha} over 1010 years. These results have also led to improved understandings in the molecular structure. The study of the low magnetic field behavior of OH in its 2{pi}3/2 ro-vibronic ground state precisely determines a differential Lande g-factor between opposite parity components of the {lambda}-doublet.
- OSTI ID:
- 20894905
- Journal Information:
- AIP Conference Proceedings, Vol. 869, Issue 1; Conference: ICAP 2006: 20. international conference on atomic physics, Innsbruck (Austria), 16-21 Jul 2006; Other Information: DOI: 10.1063/1.2400637; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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