Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0901.1526 · Journal of the Physical Society of Japan

Coherence of Spin-Polarized Fermions Interacting with a Clock Laser in a Stark-Shift-Free Optical Lattice

Masao Takamoto, Hidetoshi Katori

Published Dec 25, 2008• 19 citations
arXivHTMLPDF

Abstract

We investigated the coherence of spin-polarized ^{87}Sr atoms trapped in a light-shift-free one-dimensional optical lattice during their interaction with a clock laser on the ^1S_0-^3P_0 transition. Collapses and revivals appeared for more than 50 Rabi cycles, attributed to the thermal distribution of discrete vibrational states in the lattice potential. The population oscillation in the clock states lasted more than 1s, demonstrating high immunity from decoherence. This long atomic coherence suggests the feasibility of Pauli blocking of collisions in optical clock excitation.

DOI
10.1143/jpsj.78.013301

Related papers

Optical lattice clocks toward 10-17uncertainty

Masao Takamoto, Tomoya Akatsuka, Hidekazu Hachisu +1 more

We discuss two possible configurations for optical lattice clocks; a one-dimensional (1D) lattice loaded with spinpolarized fermions, and a three-dimensional (3D) lattice loaded with bosons. In the former scheme, collisional frequency shifts are suppressed by the quantum statistical property of identical fermions. This Pauli blocking of collisions is critically dependent on the degree of spin polarization of the fermionic atoms, which we carefully investigated in the Rabi excitation process of the clock transition. In the latter scheme, a single occupancy lattice suppresses bunching of bosons and collisional frequency shifts. We demonstrate a frequency comparison of these two optical lattice clocks based on fermionic 87Sr and bosonic 88Sr. Operating these clocks parallely has yielded a stability approaching 10−17. Such measurements are an important step to ascertain the lattice clocks' uncertainty at the 10−17 level and beyond.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 20, 2009•0 citations

Observation of Spin Polarized Clock Transition in 87 Sr Optical Lattice Clock

Qiang Wang, Yige Lin, Ye Li +5 more

We report our observation of the spin polarized 1 S 0 → 3 P 0 clock transition spectrum in an optical lattice clock based on fermionic 87 Sr. The atoms are trapped and pre-cooled to about 2 μK with two stages of laser cooling at 461 nm and 689 nm, respectively. Then the atoms are loaded into an optical lattice formed by the interference of counter-propagating laser beams at 813 nm. An external cavity diode laser at 698 nm, which is stabilized to a high finesse cavity with a linewidth of about 5 Hz and a drift rate of less than 0.2 Hz/s, is used to excite the atoms to the 3 P 0 state. The π-polarized clock transition spectrum of resolvable m F states is obtained by applying a small bias magnetic field along the polarization axis of the probe beam. A spin polarized clock transition spectrum as narrow as 10 Hz with an 80 ms probe pulse is obtained.

Chinese Physics Letters•Dec 1, 2014•8 citations

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.

Physical Review A•Feb 4, 2010•79 citations

Interrogation of spin polarized clock transition in strontium optical lattice clock

Yang Guo, Yin Mo-Juan, Qinfang Xu +5 more

We demonstrate a spin-polarized clock transition spectrum of the 87Sr optical lattice clock. The clock transition 5s2 1S05s5p 3P0 of isotope 87Sr has a hyperfine structure due to non-zero nuclear spin, inducing ten -polarized transitions from each individual mF state under the condition of a bias magnetic field along the probing polarization axis. In this experiment, atoms are driven to a certain mF state by a circular-polarization pump light to maximize the atomic population, which is beneficial to the stability and uncertainty evaluation of the optical lattice clock. After two stages cooling and trapping, about 3.5106 atoms are trapped in the red magneto-optical trap with a temperature of 3.9 K. A grating-feedback external cavity diode laser with a tapered amplifier is used to build the optical lattice with a magic-wavelength of 813.426 nm. Both waists of the counter-propagating lattice beam along the horizontal direction are overlapped to form a one-dimensional (1D) optical lattice. The lifetime of the atoms trapped in the 1D optical lattice is 1600 ms. The clock laser at 698 nm is a grating-feedback diode laser, which is locked to an ultra-low expansion cavity by the Pound-Drever-Hall technique to stabilize the frequency and phase. As a result, the linewidth of clock laser is narrowed to Hz level. By the normalized shelving method, we obtain a resolved sideband spectrum of 87Sr 5s2 1S05s5p 3P0 transition. According to the spectrum, the lattice temperature along the longitudinal direction is approximately 4.2 K. After that a linewidth of 6.7 Hz of the degenerate clock transition is obtained at a probing time of 150 ms by utilizing a three-dimensional (3D) bias magnetic field, which is used to eliminate the stray magnetic fields. Then a small bias magnetic field of 300 mGs is applied along the polarization axis of the lattice light to achieve the spectrum of Zeeman magnetic sublevels of the clock transition. Furthermore, the mF=+9/2 and mF=-9/2 magnetic sublevels are picked to be respectively pumped by the +-polarized and --polarized light at 689 nm, a variable liquid crystal wave plate is employed to switch on both polarizations. Finally, the spin polarized clock transition spectrum is obtained at the interrogating pulse of 150 ms, and the linewidths of the mF=+9/2, mF=-9/2 magnetic sublevel transitions are 6.8 Hz and 6.2 Hz respectively.

Acta Physica Sinica•Jan 1, 2018•1 citation

Improved Frequency Measurement of a One-Dimensional Optical Lattice Clock with a Spin-Polarized Fermionic87Sr Isotope

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.

arXiv:physics/0608212•Journal of the Physical Society of Japan•Oct 10, 2006•125 citations

Many-Body Physics in an Optical Lattice Clock

Sarah Bromley

In this work we study the effect of interactions in an optical lattice clock based on fermionic Sr atoms. In current one-dimensional lattice clocks nuclear spin-polarized atoms are known to have contact interactions of p-wave character and collective in nature. Here we focus on interactions that will influence the design of future optical lattice clocks. We study the case where atoms are no longer confined to a single nuclear spin state. By using samples of atoms with different distributions among the ten nuclear spin states of Sr we show that these interactions are SU(N) symmetric up to a 3% uncertainty in our measurements. Through these measurements we are also able to determine all the s-wave and p-wave scattering lengths.\nWe also study the case of nuclear spin-polarized interacting atoms that are allowed to tunnel between different lattice sites where the electronic spin and the motion of these atoms become coupled. We observe spectroscopically the precession of the collective magnetization and evolution of spin locking effects arising from the interplay between p-wave interactions and interactions induced by the spin-orbit coupling. The many-body dynamics are captured by a spin model that describes a broad class of condensed matter systems ranging from superconductors to quantum magnets.\nBy loading a dense sample of atoms into a magneto-optical trap we are able to observe long-range dipole-dipole interactions between our Sr atoms. These interactions will be important for atomic clocks based on a three dimensional lattice, such as the one recently demonstrated in our lab. In these clocks it is possible to remove the contact interactions between the atoms by loading only one atom per lattice site. In this case the dominant interactions will be from the long-range dipole-dipole interactions that will take place between the atoms.

•Jan 1, 2018•0 citations
We investigated the coherence of spin-polarized ^{87}Sr atoms trapped in a light-shift-free one-dimensional optical lattice during their interaction with a clock laser on the ^1S_0-^3P_0 transition. Collapses and revivals appeared for more than 50 Rabi cycles, attributed to the thermal distribution of discrete vibrational states in the lattice potential. The population oscillation in the clock states lasted more than 1s, demonstrating high immunity from decoherence. This long atomic coherence suggests the feasibility of Pauli blocking of collisions in optical clock excitation.
We discuss two possible configurations for optical lattice clocks; a one-dimensional (1D) lattice loaded with spinpolarized fermions, and a three-dimensional (3D) lattice loaded with bosons. In the former scheme, collisional frequency shifts are suppressed by the quantum statistical property of identical fermions. This Pauli blocking of collisions is critically dependent on the degree of spin polarization of the fermionic atoms, which we carefully investigated in the Rabi excitation process of the clock transition. In the latter scheme, a single occupancy lattice suppresses bunching of bosons and collisional frequency shifts. We demonstrate a frequency comparison of these two optical lattice clocks based on fermionic 87Sr and bosonic 88Sr. Operating these clocks parallely has yielded a stability approaching 10−17. Such measurements are an important step to ascertain the lattice clocks' uncertainty at the 10−17 level and beyond.
We report our observation of the spin polarized 1 S 0 → 3 P 0 clock transition spectrum in an optical lattice clock based on fermionic 87 Sr. The atoms are trapped and pre-cooled to about 2 μK with two stages of laser cooling at 461 nm and 689 nm, respectively. Then the atoms are loaded into an optical lattice formed by the interference of counter-propagating laser beams at 813 nm. An external cavity diode laser at 698 nm, which is stabilized to a high finesse cavity with a linewidth of about 5 Hz and a drift rate of less than 0.2 Hz/s, is used to excite the atoms to the 3 P 0 state. The π-polarized clock transition spectrum of resolvable m F states is obtained by applying a small bias magnetic field along the polarization axis of the probe beam. A spin polarized clock transition spectrum as narrow as 10 Hz with an 80 ms probe pulse is obtained.
We present detailed analyses of our recent experiment on the three-dimensional (3D) optical lattice clock with bosonic 88Sr^{88}\mathrm{Sr}88Sr atoms in which the collisional frequency shift was suppressed by applying a single-occupancy lattice. Frequency shifts in magnetically induced spectroscopy on the 1S0−−3P0{}^{1}{S}_{0}--{}^{3}{P}_{0}1S0​−−3P0​ clock transition ($\ensuremath{\lambda}=698$ nm) of 88Sr^{88}\mathrm{Sr}88Sr were experimentally investigated by referencing a one-dimensional (1D) lattice clock based on spin-polarized 87Sr^{87}\mathrm{Sr}87Sr 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 demonstrate a spin-polarized clock transition spectrum of the 87Sr optical lattice clock. The clock transition 5s2 1S05s5p 3P0 of isotope 87Sr has a hyperfine structure due to non-zero nuclear spin, inducing ten -polarized transitions from each individual mF state under the condition of a bias magnetic field along the probing polarization axis. In this experiment, atoms are driven to a certain mF state by a circular-polarization pump light to maximize the atomic population, which is beneficial to the stability and uncertainty evaluation of the optical lattice clock. After two stages cooling and trapping, about 3.5106 atoms are trapped in the red magneto-optical trap with a temperature of 3.9 K. A grating-feedback external cavity diode laser with a tapered amplifier is used to build the optical lattice with a magic-wavelength of 813.426 nm. Both waists of the counter-propagating lattice beam along the horizontal direction are overlapped to form a one-dimensional (1D) optical lattice. The lifetime of the atoms trapped in the 1D optical lattice is 1600 ms. The clock laser at 698 nm is a grating-feedback diode laser, which is locked to an ultra-low expansion cavity by the Pound-Drever-Hall technique to stabilize the frequency and phase. As a result, the linewidth of clock laser is narrowed to Hz level. By the normalized shelving method, we obtain a resolved sideband spectrum of 87Sr 5s2 1S05s5p 3P0 transition. According to the spectrum, the lattice temperature along the longitudinal direction is approximately 4.2 K. After that a linewidth of 6.7 Hz of the degenerate clock transition is obtained at a probing time of 150 ms by utilizing a three-dimensional (3D) bias magnetic field, which is used to eliminate the stray magnetic fields. Then a small bias magnetic field of 300 mGs is applied along the polarization axis of the lattice light to achieve the spectrum of Zeeman magnetic sublevels of the clock transition. Furthermore, the mF=+9/2 and mF=-9/2 magnetic sublevels are picked to be respectively pumped by the +-polarized and --polarized light at 689 nm, a variable liquid crystal wave plate is employed to switch on both polarizations. Finally, the spin polarized clock transition spectrum is obtained at the interrogating pulse of 150 ms, and the linewidths of the mF=+9/2, mF=-9/2 magnetic sublevel transitions are 6.8 Hz and 6.2 Hz respectively.
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 1S0(F=9/2)−3P0(F=9/2)^1S_0(F=9/2) - {}^3P_0(F=9/2)1S0​(F=9/2)−3P0​(F=9/2) clock transition of the 87^{87}87Sr 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.
In this work we study the effect of interactions in an optical lattice clock based on fermionic Sr atoms. In current one-dimensional lattice clocks nuclear spin-polarized atoms are known to have contact interactions of p-wave character and collective in nature. Here we focus on interactions that will influence the design of future optical lattice clocks. We study the case where atoms are no longer confined to a single nuclear spin state. By using samples of atoms with different distributions among the ten nuclear spin states of Sr we show that these interactions are SU(N) symmetric up to a 3% uncertainty in our measurements. Through these measurements we are also able to determine all the s-wave and p-wave scattering lengths.\nWe also study the case of nuclear spin-polarized interacting atoms that are allowed to tunnel between different lattice sites where the electronic spin and the motion of these atoms become coupled. We observe spectroscopically the precession of the collective magnetization and evolution of spin locking effects arising from the interplay between p-wave interactions and interactions induced by the spin-orbit coupling. The many-body dynamics are captured by a spin model that describes a broad class of condensed matter systems ranging from superconductors to quantum magnets.\nBy loading a dense sample of atoms into a magneto-optical trap we are able to observe long-range dipole-dipole interactions between our Sr atoms. These interactions will be important for atomic clocks based on a three dimensional lattice, such as the one recently demonstrated in our lab. In these clocks it is possible to remove the contact interactions between the atoms by loading only one atom per lattice site. In this case the dominant interactions will be from the long-range dipole-dipole interactions that will take place between the atoms.