We analyze doubly magic trapping of Cs hyperfine transitions including previously neglected contributions from the ground state hyperpolarizability and the interaction of the laser light and a static magnetic field. Extensive numerical searches do not reveal any doubly magic trapping conditions for any pair of hyperfine states. However, including the hyperpolarizability reveals light intensity insensitive traps for a wide range of wavelengths at specific intensities. We then investigate the possibility of using bichromatic trapping light fields. Deploying a bichromatic scheme, we demonstrate doubly magic red and blue detuned traps for pairs of states separated by one or two single photon transitions.We analyze doubly magic trapping of Cs hyperfine transitions including previously neglected contributions from the ground state hyperpolarizability and the interaction of the laser light and a static magnetic field. Extensive numerical searches do not reveal any doubly magic trapping conditions for any pair of hyperfine states. However, including the hyperpolarizability reveals light intensity insensitive traps for a wide range of wavelengths at specific intensities. We then investigate the possibility of using bichromatic trapping light fields. Deploying a bichromatic scheme, we demonstrate doubly magic red and blue detuned traps for pairs of states separated by one or two single photon transitions.

Jun 13, 20142 citations

“Doubly Magic” Conditions in Magic-Wavelength Trapping of Ultracold Alkali-Metal Atoms

Andrei Derevianko

In experiments with trapped atoms, atomic energy levels are shifted by the trapping optical and magnetic fields. Regardless of this strong perturbation, precision spectroscopy may be still carried out using specially crafted, "magic" trapping fields. Finding these conditions for particularly valuable microwave transitions in alkali-metal atoms has so far remained an open challenge. Here I demonstrate that the microwave transitions in alkali-metal atoms may be indeed made impervious to both trapping laser intensity and fluctuations of magnetic fields. I consider driving multiphoton transitions between the clock levels and show that these "doubly magic" conditions are realized at special values of trapping laser wavelengths and fixed values of relatively weak magnetic fields. This finding has implications for precision measurements and quantum information processing with qubits stored in hyperfine manifolds.In experiments with trapped atoms, atomic energy levels are shifted by the trapping optical and magnetic fields. Regardless of this strong perturbation, precision spectroscopy may be still carried out using specially crafted, "magic" trapping fields. Finding these conditions for particularly valuable microwave transitions in alkali-metal atoms has so far remained an open challenge. Here I demonstrate that the microwave transitions in alkali-metal atoms may be indeed made impervious to both trapping laser intensity and fluctuations of magnetic fields. I consider driving multiphoton transitions between the clock levels and show that these "doubly magic" conditions are realized at special values of trapping laser wavelengths and fixed values of relatively weak magnetic fields. This finding has implications for precision measurements and quantum information processing with qubits stored in hyperfine manifolds.

arXiv:1004.2941Physical Review LettersJul 16, 201034 citations

Magnetic-sublevel-independent magic wavelengths: Application to Rb and Cs atoms

Sukhjit Singh Sehra, B. K. Sahoo, Bindiya Arora

A generic scheme to trap atoms at the magic wavelengths ${\ensuremath{\lambda}}_{\mathrm{magic}}$ that are independent of vector and tensor components of the interactions of the atoms with the external electric field is presented. The ${\ensuremath{\lambda}}_{\mathrm{magic}}$ for the laser cooling ${D}_{2}$ lines in the Rb and Cs atoms are demonstrated and their corresponding polarizability values without vector and tensor contributions are given. Consequently, these ${\ensuremath{\lambda}}_{\mathrm{magic}}$ are independent of magnetic sublevels and hyperfine levels of the atomic states involved in the transition, thus, they can offer unique approaches to carrying out many high-precision measurements with minimal systematics. Inevitably, the proposed technique can also be used for electronic or hyperfine transitions in other atomic systems.A generic scheme to trap atoms at the magic wavelengths ${\ensuremath{\lambda}}_{\mathrm{magic}}$ that are independent of vector and tensor components of the interactions of the atoms with the external electric field is presented. The ${\ensuremath{\lambda}}_{\mathrm{magic}}$ for the laser cooling ${D}_{2}$ lines in the Rb and Cs atoms are demonstrated and their corresponding polarizability values without vector and tensor contributions are given. Consequently, these ${\ensuremath{\lambda}}_{\mathrm{magic}}$ are independent of magnetic sublevels and hyperfine levels of the atomic states involved in the transition, thus, they can offer unique approaches to carrying out many high-precision measurements with minimal systematics. Inevitably, the proposed technique can also be used for electronic or hyperfine transitions in other atomic systems.

arXiv:1606.05414Physical Review AJun 24, 201614 citations

Triply Magic Conditions for Microwave Transition of Optically Trapped Alkali-Metal Atoms

Gang Li, Yali Tian, Wei Wu +5 more

We report the finding of "triply magic" conditions (the doubly magic frequency-intensity conditions of an optical dipole trap plus the magic magnetic field) for the microwave transitions of optically trapped alkali-metal atoms. The differential light shift (DLS) induced by a degenerate two-photon process is adopted to compensate a DLS associated with the one-photon process. Thus, doubly magic conditions for the intensity and frequency of the optical trap beam can be found. Moreover, the DLS decouples from the magnetic field in a linearly polarized optical dipole trap, so that the magic condition of the magnetic field can be applied independently. Therefore, the triply magic conditions can be realized simultaneously. We also experimentally demonstrate the doubly magic frequency-intensity conditions as well as the independence of the magnetic field. When the triply magic conditions are fulfilled, the inhomogeneous and homogeneous decoherences for the optically trapped atom will be dramatically suppressed, and the coherence time can be extended significantly.We report the finding of "triply magic" conditions (the doubly magic frequency-intensity conditions of an optical dipole trap plus the magic magnetic field) for the microwave transitions of optically trapped alkali-metal atoms. The differential light shift (DLS) induced by a degenerate two-photon process is adopted to compensate a DLS associated with the one-photon process. Thus, doubly magic conditions for the intensity and frequency of the optical trap beam can be found. Moreover, the DLS decouples from the magnetic field in a linearly polarized optical dipole trap, so that the magic condition of the magnetic field can be applied independently. Therefore, the triply magic conditions can be realized simultaneously. We also experimentally demonstrate the doubly magic frequency-intensity conditions as well as the independence of the magnetic field. When the triply magic conditions are fulfilled, the inhomogeneous and homogeneous decoherences for the optically trapped atom will be dramatically suppressed, and the coherence time can be extended significantly.

arXiv:1905.11094Physical Review LettersDec 20, 201915 citations

Bichromatic state-independent trapping of caesium atoms

M.M. Metbulut

State-insensitive trapping plays a significant role in many cold atom experiments. In this technique, trapping at a specific "magic" wavelength leads to identical shifts of the ground and excited states of a particular transition. Hence, the internal state of the trapped atoms remains essentially unaffected by the trapping light. This leads to increased coherence times and loading efficiency, and allows for the use of free-space manipulation techniques. However, the applicability of state-insensitive trapping is limited in terms of light sources available, with restrictions coming from either the required frequency or power. In this thesis, state-insensitive trapping of caesium atoms is considered. It can be achieved at the wavelength of 935.6 nm. However, the present work shows that this wavelength is impractical for experimental realizations of atom trapping in free space due to lack of laser sources with sufficiently high power. We therefore propose bichromatic trapping, as produced by two independent laser fields with different frequencies, to overcome the limitations related to monochromatic trapping. We show that bichromatic trapping extends the range of possible magic wavelengths compared to the specific magic wavelength associated with monochromatic trapping. Specifically, we present results for the magic wavelength combinations for caesium atoms with particular attention to the frequency range of currently available laser sources. Simultaneous state-independent trapping of atomic mixtures of caesium with rubidium and lithium atoms was also investigated, and appropriate magic wavelength combinations were identified. Additionally, species-selective state-independent trapping of atomic mixtures of caesium and lithium was explored and common wavelength pairs for tune-out and magic wavelengths of these atoms were determined.State-insensitive trapping plays a significant role in many cold atom experiments. In this technique, trapping at a specific "magic" wavelength leads to identical shifts of the ground and excited states of a particular transition. Hence, the internal state of the trapped atoms remains essentially unaffected by the trapping light. This leads to increased coherence times and loading efficiency, and allows for the use of free-space manipulation techniques. However, the applicability of state-insensitive trapping is limited in terms of light sources available, with restrictions coming from either the required frequency or power. In this thesis, state-insensitive trapping of caesium atoms is considered. It can be achieved at the wavelength of 935.6 nm. However, the present work shows that this wavelength is impractical for experimental realizations of atom trapping in free space due to lack of laser sources with sufficiently high power. We therefore propose bichromatic trapping, as produced by two independent laser fields with different frequencies, to overcome the limitations related to monochromatic trapping. We show that bichromatic trapping extends the range of possible magic wavelengths compared to the specific magic wavelength associated with monochromatic trapping. Specifically, we present results for the magic wavelength combinations for caesium atoms with particular attention to the frequency range of currently available laser sources. Simultaneous state-independent trapping of atomic mixtures of caesium with rubidium and lithium atoms was also investigated, and appropriate magic wavelength combinations were identified. Additionally, species-selective state-independent trapping of atomic mixtures of caesium and lithium was explored and common wavelength pairs for tune-out and magic wavelengths of these atoms were determined.

Apr 28, 20160 citations

Theory of magic optical traps for Zeeman-insensitive clock transitions in alkali-metal atoms

Andrei Derevianko

Precision measurements and quantum-information processing with cold atoms may benefit from trapping atoms with specially engineered, ``magic'' optical fields. At the magic trapping conditions, the relevant atomic properties remain immune to strong perturbations by the trapping fields. Here we develop a theoretical analysis of magic trapping for especially valuable Zeeman-insensitive clock transitions in alkali-metal atoms. The involved mechanism relies on applying a magic bias $B$ field along a circularly polarized trapping laser field. We map out these $B$ fields as a function of trapping laser wavelength for all commonly used alkalis. We also highlight a common error in evaluating Stark shifts of hyperfine manifolds.Precision measurements and quantum-information processing with cold atoms may benefit from trapping atoms with specially engineered, ``magic'' optical fields. At the magic trapping conditions, the relevant atomic properties remain immune to strong perturbations by the trapping fields. Here we develop a theoretical analysis of magic trapping for especially valuable Zeeman-insensitive clock transitions in alkali-metal atoms. The involved mechanism relies on applying a magic bias $B$ field along a circularly polarized trapping laser field. We map out these $B$ fields as a function of trapping laser wavelength for all commonly used alkalis. We also highlight a common error in evaluating Stark shifts of hyperfine manifolds.

arXiv:0912.3233Physical Review AMay 20, 201045 citations

{D}_{2}

lines in the Rb and Cs atoms are demonstrated and their corresponding polarizability values without vector and tensor contributions are given. Consequently, these ${\ensuremath{\lambda}}_{\mathrm{magic}}$ are independent of magnetic sublevels and hyperfine levels of the atomic states involved in the transition, thus, they can offer unique approaches to carrying out many high-precision measurements with minimal systematics. Inevitably, the proposed technique can also be used for electronic or hyperfine transitions in other atomic systems.

B

field along a circularly polarized trapping laser field. We map out these

B

fields as a function of trapping laser wavelength for all commonly used alkalis. We also highlight a common error in evaluating Stark shifts of hyperfine manifolds.