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The blackbody radiation (BBR) shift is an important systematic correction for the atomic frequency standards realizing the SI unit of time. Presently, there is controversy over the value of the BBR shift for the primary 133Cs standard. At room temperatures, the values from various groups differ at the 3x10(-15) level, while modern clocks are aiming at(More)
Atomic clocks have been instrumental in science and technology, leading to innovations such as global positioning, advanced communications, and tests of fundamental constant variation. Timekeeping precision at 1 part in 10(18) enables new timing applications in relativistic geodesy, enhanced Earth- and space-based navigation and telescopy, and new tests of(More)
We carry out high-precision calculation of parity violation in a cesium atom, reducing theoretical uncertainty by a factor of 2 compared to previous evaluations. We combine previous measurements with calculations and extract the weak charge of the 133Cs nucleus, QW=-73.16(29)expt(20)theor. The result is in agreement with the standard model (SM) of(More)
S.G. Porsev, K. Beloy, and A. Derevianko Physics Department, University of Nevada, Reno, Nevada 89557, USA School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia Petersburg Nuclear Physics Institute, Gatchina, Leningrad District 188300, Russia Centre for Theoretical Chemistry and Physics, The New Zealand Institute for(More)
The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for(More)
Microwave atomic clocks are based on the intrinsic hyperfine energy interval in the ground state of an atom. In the presence of an oscillating electric field, the atomic system—namely, the hyperfine interval—becomes perturbed (the ac Stark effect). For the atomic sample in a clock, such a perturbation leads to an undesired shift in the clock frequency and,(More)
We propose a new class of atomic microwave clocks based on the hyperfine transitions in the ground state of aluminum or gallium atoms trapped in optical lattices. For such elements magic wavelengths exist at which both levels of the hyperfine doublet are shifted at the same rate by the lattice laser field, cancelling its effect on the clock transition. A(More)
We identify a potential means to extract the 229gTh→ 229mTh nuclear excitation energy from precision microwave spectroscopy of the 5F(5/2,7/2) hyperfine manifolds in the ion 229gTh3+. The hyperfine interaction mixes this ground fine structure doublet with states of the nuclear isomer, introducing small but observable shifts to the hyperfine sublevels. We(More)
The dual-kinetic-balance (DKB) finite basis set method for solving the Dirac equation for hydrogen-like ions [V.M. Shabaev et al., Phys. Rev. Lett. 93 (2004) 130405] is extended to problems with a non-local spherically-symmetric Dirac–Hartree–Fock potential. We implement the DKB method using B-spline basis sets and compare its performance with the(More)
A scheme is presented for entangling the atoms of an optical lattice to reduce the quantum projection noise of a clock measurement. The divalent clock atoms are held in a lattice at a “magic” wavelength that does not perturb the clock frequency—to maintain clock accuracy—while an open-shell J = 1/2 “head” atom is coherently transported between lattice sites(More)