[en] 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 via the lattice polarization. This polarization-dependent 'Archimedes' screw' transport at magic wavelength takes advantage of the vanishing vector polarizability of the scalar, J=0, clock states of bosonic isotopes of divalent atoms. The on-site interactions between the clock atoms and the head atom are used to engineer entanglement and for clock readout.

[en] Electromagnetically induced transparency in a multilevel system is investigated in ¹⁷³Yb. The level structure investigated is ''open'' in that the light that gives rise to the transparency also resonantly couples the atoms to excited states which do not exhibit electromagnetically induced transparency. The resulting reduction of transparency is investigated experimentally and theoretically. It is found that, while the transparency is poor in certain regimes, it can be made to perform arbitrarily well in the limit of a large intensity imbalance between the optical fields.

[en] A sample of cryogenically cooled atomic ytterbium is used to create a memory for a classical pulse of light. The information of the light pulse is stored in the nuclear spin of ground-state (¹S₀) ¹⁷³Yb (I=5/2). Because nuclear spin states interact very weakly with their environment, the atomic ensemble is resistant to decoherence due to inelastic collisions and inhomogeneous fields, and storage times of hundreds of milliseconds are observed.

[en] We have measured cold inelastic collisions between neutral ground-state titanium atoms: collisions that cause transitions between the different magnetic sublevels of the [3d²4s²]³F₂ ground state of ⁵⁰Ti, as well as collisions that cause transitions between the fine-structure levels of the [3d²4s²]³F_J electronic ground state. Both processes occur with large rate coefficients, as would be expected from titanium's anisotropic electronic potential.

[en] We use laser ablation and cryogenic helium buffer-gas cooling to produce large numbers of X³Δ₁ TiO molecules at a translational temperature of 5 K. We investigate their cold collisions with helium and measure elastic and inelastic scattering cross-sections. As expected for ³Δ molecules, which have large spin-rotation couplings, TiO's inelastic m-changing collision cross-section is large: on the same order as its momentum transfer cross-section.

[en] We report the magnetic trapping and evaporative cooling of bosonic and fermionic isotopes of atomic chromium. Using a cryogenic helium buffer gas, 10¹² chromium atoms are trapped at an initial temperature of ∼1 K. The chromium atoms are then cooled adiabatically and evaporatively to temperatures as low as ∼10 mK. Elastic and inelastic ⁵²Cr collisional cross sections are measured over this temperature range. Prospects for simultaneously creating a ⁵²Cr Bose-Einstein condensate and ⁵³Cr Fermi degenerate gas will be discussed

[en] We have produced a cryogenic buffer-gas cooled beam of the diatomic molecular radical CH (methylidyne). This molecule is of interest for studying cold chemical reactions and fundamental physics measurements. Its light mass and ground-state structure make it a promising candidate for electrostatic guiding and Stark deceleration, which allows for control over its kinetic energy. This control can facilitate studies of reactions with tuneable collision energies and trapping for precise spectroscopic studies. Here, we have demonstrated electrostatic guiding of CH with fluxes up to 10⁹ molecules per steradian per pulse.

[en] We have performed a type of Autler-Townes spectroscopy to locate a number of rovibrational-hyperfine levels of the a ³Σ_u⁺ potential, the lowest triplet potential of the Na₂ dimer. The spectroscopy starts with the photoassociation of ultracold atoms in a magneto-optical trap. We have measured the binding energies of over 100 individual states spanning the vibrational levels v=8-15 of this potential (binding energies up to 27 cm^-1). We obtain a typical accuracy of 15 MHz and a typical resolution of 20 MHz, improving on the 10 GHz accuracy and 30 GHz resolution previously available for the vibrational states v<12. Vibrational, rotational, and hyperfine structures are resolved. Additionally, we have been able to resolve the magnetic electron-electron spin-spin dipole splitting of a number of these hyperfine levels. The measured rotational and hyperfine structures show good agreement with theoretical calculations. An analysis of the remaining discrepancies indicates where possible refinements to the potentials can be made. We also observe evidence for the presence of second-order spin-orbit coupling