We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped $^{87}\mathrm{Rb}$ atoms. Recent progress in metrology exploits so-called magic wavelengths, whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkali metals due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically trapped neutral atoms.We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped $^{87}\mathrm{Rb}$ atoms. Recent progress in metrology exploits so-called magic wavelengths, whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkali metals due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically trapped neutral atoms.

arXiv:0912.1528Physical Review AMar 29, 201065 citations

Magic Polarization for Optical Trapping of Atoms without Stark-Induced Dephasing

Huidong Kim, Hyok Sang Han, D. Cho

We demonstrate that the differential ac-Stark shift of a Zeeman-sensitive ground hyperfine transition in an optical trap can be eliminated by using properly polarized trapping light. We use the vector polarizability of an alkali-metal atom to produce a polarization-dependent ac-Stark shift that resembles a Zeeman shift. We study a transition from the $|2{S}_{1/2},F=2,{m}_{F}=\ensuremath{-}2⟩$ to the $|2{S}_{1/2},F=1,{m}_{F}=\ensuremath{-}1⟩$ state of $^{7}\mathrm{Li}$ to observe $0.59\ifmmode\pm\else\textpm\fi{}0.02\text{ }\text{ }\mathrm{Hz}$ linewidth with interrogation time of 2 s and $0.82\ifmmode\pm\else\textpm\fi{}0.06\text{ }\text{ }\mathrm{s}$ coherence time of a superposition state. Implications of the narrow linewidth and the long coherence time for precision spectroscopy and quantum information processing using atoms in an optical lattice are discussed.We demonstrate that the differential ac-Stark shift of a Zeeman-sensitive ground hyperfine transition in an optical trap can be eliminated by using properly polarized trapping light. We use the vector polarizability of an alkali-metal atom to produce a polarization-dependent ac-Stark shift that resembles a Zeeman shift. We study a transition from the $|2{S}_{1/2},F=2,{m}_{F}=\ensuremath{-}2⟩$ to the $|2{S}_{1/2},F=1,{m}_{F}=\ensuremath{-}1⟩$ state of $^{7}\mathrm{Li}$ to observe $0.59\ifmmode\pm\else\textpm\fi{}0.02\text{ }\text{ }\mathrm{Hz}$ linewidth with interrogation time of 2 s and $0.82\ifmmode\pm\else\textpm\fi{}0.06\text{ }\text{ }\mathrm{s}$ coherence time of a superposition state. Implications of the narrow linewidth and the long coherence time for precision spectroscopy and quantum information processing using atoms in an optical lattice are discussed.

arXiv:1311.1290Physical Review LettersDec 11, 201334 citations

Experimental Observation of Magic-Wavelength Behavior in Optical Lattice-Trapped 87 Rb | NIST

J. V. Porto, Nathan E. Lundblad, Malte Schlosser

We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped 87 Rb atoms. Recent progress in metrology exploits so-called “magic wavelengths,” whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkalis, due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically-trapped neutral atoms.We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped 87 Rb atoms. Recent progress in metrology exploits so-called “magic wavelengths,” whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkalis, due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically-trapped neutral atoms.

Physical Review LettersMar 29, 20101 citation

We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped

^{87}\mathrm{Rb}

atoms. Recent progress in metrology exploits so-called magic wavelengths, whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkali metals due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically trapped neutral atoms.

^{7}\mathrm{Li}

to observe $0.59\ifmmode\pm\else\textpm\fi{}0.02\text{ }\text{ }\mathrm{Hz}$ linewidth with interrogation time of 2 s and $0.82\ifmmode\pm\else\textpm\fi{}0.06\text{ }\text{ }\mathrm{s}$ coherence time of a superposition state. Implications of the narrow linewidth and the long coherence time for precision spectroscopy and quantum information processing using atoms in an optical lattice are discussed.