arXiv:0904.2515 · Physical Review Letters

Collisional Losses, Decoherence, and Frequency Shifts in Optical Lattice Clocks with Bosons

Christian Lisdat, J. S. Raaj Vellore Winfred, Thomas Middelmann, F. Riehle, Uwe Sterr

Published Aug 28, 2009• 87 citations

Abstract

We have quantified collisional losses, decoherence and the collision shift in a one-dimensional optical lattice clock on the highly forbidden transition (1)S(0)-(3)P(0) at 698 nm with bosonic (88)Sr. We were able to distinguish two loss channels: inelastic collisions between atoms in the upper and lower clock state and atoms in the upper clock state only. Based on the measured coefficients, we determine the operation parameters at which a 1D-lattice clock with (88)Sr shows no degradation due to collisions on the fractional uncertainty level of 10(-16).

DOI: 10.1103/physrevlett.103.090801

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arXiv:0904.2515 · Physical Review Letters

Collisional Losses, Decoherence, and Frequency Shifts in Optical Lattice Clocks with Bosons

Christian Lisdat, J. S. Raaj Vellore Winfred, Thomas Middelmann, F. Riehle, Uwe Sterr

Published Aug 28, 2009• 87 citations

arXiv HTML PDF

Abstract

DOI: 10.1103/physrevlett.103.090801

Related papers

Three-dimensional optical lattice clock with bosonic Sr 88 atoms

Tomoya Akatsuka, Masao Takamoto, Hidetoshi Katori

We present detailed analyses of our recent experiment on the three-dimensional (3D) optical lattice clock with bosonic $^{88}\mathrm{Sr}$ atoms in which the collisional frequency shift was suppressed by applying a single-occupancy lattice. Frequency shifts in magnetically induced spectroscopy on the ${}^{1}{S}_{0}--{}^{3}{P}_{0}$ clock transition ($\ensuremath{\lambda}=698$ nm) of $^{88}\mathrm{Sr}$ were experimentally investigated by referencing a one-dimensional (1D) lattice clock based on spin-polarized $^{87}\mathrm{Sr}$ atoms. We discuss that the clock stability is limited by the current laser stability as well as the experimental sequence of the clock operation, which may be improved to ${\ensuremath{\sigma}}_{y}(\ensuremath{\tau})=2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}/\sqrt{\ensuremath{\tau}}$ by optimizing the cycle time of the clock operation.We present detailed analyses of our recent experiment on the three-dimensional (3D) optical lattice clock with bosonic $^{88}\mathrm{Sr}$ atoms in which the collisional frequency shift was suppressed by applying a single-occupancy lattice. Frequency shifts in magnetically induced spectroscopy on the ${}^{1}{S}_{0}--{}^{3}{P}_{0}$ clock transition ($\ensuremath{\lambda}=698$ nm) of $^{88}\mathrm{Sr}$ were experimentally investigated by referencing a one-dimensional (1D) lattice clock based on spin-polarized $^{87}\mathrm{Sr}$ atoms. We discuss that the clock stability is limited by the current laser stability as well as the experimental sequence of the clock operation, which may be improved to ${\ensuremath{\sigma}}_{y}(\ensuremath{\tau})=2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}/\sqrt{\ensuremath{\tau}}$ by optimizing the cycle time of the clock operation.

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Optical lattice clocks toward 10-17uncertainty

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We study the influence of ultracold collisions induced by the inhomogeneous excitation on the clock-transition frequency in one- and two-dimensional shallow blue-detuned (BD) ${}^{87}$ Sr optical lattice clocks with a magic wavelength of ${\ensuremath{\lambda}}_{b}=389.889$ nm. The minimal lattice potential required to tightly confine atoms in each single lattice site is much larger than that required for a red-detuned (RD) lattice operating at ${\ensuremath{\lambda}}_{r}=813.4$ nm because of the relatively smaller magic wavelength. For a deep optical lattice, the two-body interactions of atoms in a single lattice site mainly contribute to the clock-transition frequency shift, while the intersite collisions primarily affect the collisional shift in a shallow optical lattice. For an effective misalignment angle $\ensuremath{\Delta}\ensuremath{\theta}\ensuremath{\sim}10$ mrad of the probe beam with respect to the lattice axis, the fractional collisional shifts in both one- and two-dimensional BD lattices are at the ${10}^{\ensuremath{-}16}$ level.We study the influence of ultracold collisions induced by the inhomogeneous excitation on the clock-transition frequency in one- and two-dimensional shallow blue-detuned (BD) ${}^{87}$Sr optical lattice clocks with a magic wavelength of ${\ensuremath{\lambda}}_{b}=389.889$ nm. The minimal lattice potential required to tightly confine atoms in each single lattice site is much larger than that required for a red-detuned (RD) lattice operating at ${\ensuremath{\lambda}}_{r}=813.4$ nm because of the relatively smaller magic wavelength. For a deep optical lattice, the two-body interactions of atoms in a single lattice site mainly contribute to the clock-transition frequency shift, while the intersite collisions primarily affect the collisional shift in a shallow optical lattice. For an effective misalignment angle $\ensuremath{\Delta}\ensuremath{\theta}\ensuremath{\sim}10$ mrad of the probe beam with respect to the lattice axis, the fractional collisional shifts in both one- and two-dimensional BD lattices are at the ${10}^{\ensuremath{-}16}$ level.

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Masao Takamoto, Feng-Lei Hong, Ryoichi Higashi +3 more

We demonstrate a one-dimensional optical lattice clock with a spin-polarized fermionic isotope designed to realize a collision-shift-free atomic clock with neutral atom ensembles. To reduce systematic uncertainties, we developed both Zeeman shift and vector light-shift cancellation techniques. By introducing both an H-maser and a Global Positioning System (GPS) carrier phase link, the absolute frequency of the $^1S_0(F=9/2) - {}^3P_0(F=9/2)$ clock transition of the $^{87}$ Sr optical lattice clock is determined as 429,228,004,229,875(4) Hz, where the uncertainty is mainly limited by that of the frequency link. The result indicates that the Sr lattice clock will play an important role in the scope of the redefinition of the ``second'' by optical frequency standards.We demonstrate a one-dimensional optical lattice clock with a spin-polarized fermionic isotope designed to realize a collision-shift-free atomic clock with neutral atom ensembles. To reduce systematic uncertainties, we developed both Zeeman shift and vector light-shift cancellation techniques. By introducing both an H-maser and a Global Positioning System (GPS) carrier phase link, the absolute frequency of the $^1S_0(F=9/2) - {}^3P_0(F=9/2)$ clock transition of the $^{87}$Sr optical lattice clock is determined as 429,228,004,229,875(4) Hz, where the uncertainty is mainly limited by that of the frequency link. The result indicates that the Sr lattice clock will play an important role in the scope of the redefinition of the ``second'' by optical frequency standards.

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Inelastic collisions and density-dependent excitation suppression in a 87 Sr optical lattice clock

Michael Bishof, Michael J. Martin, Matthew D. Swallows +5 more

We observe two-body loss of ${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}$ ${}^{87}$ Sr atoms trapped in a one-dimensional optical lattice. We measure loss rate coefficients for atomic samples between 1 and 6 $\ensuremath{\mu}$K that are prepared either in a single nuclear-spin sublevel or with equal populations in two sublevels. The measured temperature and nuclear-spin preparation dependence of rate coefficients agree well with calculations and reveal that rate coefficients for distinguishable atoms are only slightly enhanced over those of indistinguishable atoms. We further observe a suppression of excitation and losses during interrogation of the ${}^{1}\phantom{\rule{-0.16em}{0ex}}{S}_{0}$ -- ${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}$ transition as density increases and Rabi frequency decreases, which suggests the presence of strong interactions in our dynamically driven many-body system.We observe two-body loss of ${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}$ ${}^{87}$Sr atoms trapped in a one-dimensional optical lattice. We measure loss rate coefficients for atomic samples between 1 and 6 $\ensuremath{\mu}$K that are prepared either in a single nuclear-spin sublevel or with equal populations in two sublevels. The measured temperature and nuclear-spin preparation dependence of rate coefficients agree well with calculations and reveal that rate coefficients for distinguishable atoms are only slightly enhanced over those of indistinguishable atoms. We further observe a suppression of excitation and losses during interrogation of the ${}^{1}\phantom{\rule{-0.16em}{0ex}}{S}_{0}$--${}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}$ transition as density increases and Rabi frequency decreases, which suggests the presence of strong interactions in our dynamically driven many-body system.

arXiv:1108.1431Physical Review ANov 17, 201156 citations

We present detailed analyses of our recent experiment on the three-dimensional (3D) optical lattice clock with bosonic

^{88}\mathrm{Sr}

atoms in which the collisional frequency shift was suppressed by applying a single-occupancy lattice. Frequency shifts in magnetically induced spectroscopy on the

{}^{1}{S}_{0}--{}^{3}{P}_{0}

clock transition ($\ensuremath{\lambda}=698$ nm) of

^{88}\mathrm{Sr}

were experimentally investigated by referencing a one-dimensional (1D) lattice clock based on spin-polarized

^{87}\mathrm{Sr}

atoms. We discuss that the clock stability is limited by the current laser stability as well as the experimental sequence of the clock operation, which may be improved to ${\ensuremath{\sigma}}_{y}(\ensuremath{\tau})=2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}/\sqrt{\ensuremath{\tau}}$ by optimizing the cycle time of the clock operation.

We study the influence of ultracold collisions induced by the inhomogeneous excitation on the clock-transition frequency in one- and two-dimensional shallow blue-detuned (BD)

{}^{87}

Sr optical lattice clocks with a magic wavelength of ${\ensuremath{\lambda}}_{b}=389.889$ nm. The minimal lattice potential required to tightly confine atoms in each single lattice site is much larger than that required for a red-detuned (RD) lattice operating at ${\ensuremath{\lambda}}_{r}=813.4$ nm because of the relatively smaller magic wavelength. For a deep optical lattice, the two-body interactions of atoms in a single lattice site mainly contribute to the clock-transition frequency shift, while the intersite collisions primarily affect the collisional shift in a shallow optical lattice. For an effective misalignment angle $\ensuremath{\Delta}\ensuremath{\theta}\ensuremath{\sim}10$ mrad of the probe beam with respect to the lattice axis, the fractional collisional shifts in both one- and two-dimensional BD lattices are at the ${10}^{\ensuremath{-}16}$ level.

^1S_0(F=9/2) - {}^3P_0(F=9/2)

clock transition of the

^{87}

Sr optical lattice clock is determined as 429,228,004,229,875(4) Hz, where the uncertainty is mainly limited by that of the frequency link. The result indicates that the Sr lattice clock will play an important role in the scope of the redefinition of the ``second'' by optical frequency standards.

We observe two-body loss of

{}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}

{}^{87}

Sr atoms trapped in a one-dimensional optical lattice. We measure loss rate coefficients for atomic samples between 1 and 6 $\ensuremath{\mu}$K that are prepared either in a single nuclear-spin sublevel or with equal populations in two sublevels. The measured temperature and nuclear-spin preparation dependence of rate coefficients agree well with calculations and reveal that rate coefficients for distinguishable atoms are only slightly enhanced over those of indistinguishable atoms. We further observe a suppression of excitation and losses during interrogation of the

{}^{1}\phantom{\rule{-0.16em}{0ex}}{S}_{0}

{}^{3}\phantom{\rule{-0.16em}{0ex}}{P}_{0}

transition as density increases and Rabi frequency decreases, which suggests the presence of strong interactions in our dynamically driven many-body system.