We report the observation and manipulation of heteronuclear spin dynamics in a spin-1 mixture of ultracold $^{87}\mathrm{Rb}$ and $^{23}\mathrm{Na}$ atoms. The dynamics is driven by the interspecies spin-dependent interaction and shows a pronounced dependence on magnetic fields with influences from both linear and quadratic Zeeman shifts. Similar to the well-studied homonuclear cases, the interspecies spin dynamics can be controlled by tuning the quadratic Zeeman shift with far-detuned microwave fields. In addition, we successfully realize spin dynamics' control with vector light shifts which act as a species-selective effective magnetic field on $^{87}\mathrm{Rb}$ atoms. Both methods show negligible loss of atoms thus will be powerful techniques for investigating spin dynamics with fast temporal and high spatial resolutions.We report the observation and manipulation of heteronuclear spin dynamics in a spin-1 mixture of ultracold $^{87}\mathrm{Rb}$ and $^{23}\mathrm{Na}$ atoms. The dynamics is driven by the interspecies spin-dependent interaction and shows a pronounced dependence on magnetic fields with influences from both linear and quadratic Zeeman shifts. Similar to the well-studied homonuclear cases, the interspecies spin dynamics can be controlled by tuning the quadratic Zeeman shift with far-detuned microwave fields. In addition, we successfully realize spin dynamics' control with vector light shifts which act as a species-selective effective magnetic field on $^{87}\mathrm{Rb}$ atoms. Both methods show negligible loss of atoms thus will be powerful techniques for investigating spin dynamics with fast temporal and high spatial resolutions.

arXiv:2005.06098Physical Review AMay 7, 202011 citations

Realising a species-selective double well with multiple-radiofrequency-dressed potentials

A J Barker, S Sunami, D Garrick +4 more

Abstract Techniques to manipulate the individual constituents of an ultracold mixture are key to investigating impurity physics. In this work, we confine a mixture of hyperfine ground states of 87Rb atoms in a double-well potential. The potential is produced by dressing the atoms with multiple radiofrequencies. The amplitude and phase of each frequency component of the dressing field are controlled to independently manipulate each species. Furthermore, we verify that our mixture of hyperfine states is collisionally stable, with no observable inelastic loss.Abstract Techniques to manipulate the individual constituents of an ultracold mixture are key to investigating impurity physics. In this work, we confine a mixture of hyperfine ground states of 87Rb atoms in a double-well potential. The potential is produced by dressing the atoms with multiple radiofrequencies. The amplitude and phase of each frequency component of the dressing field are controlled to independently manipulate each species. Furthermore, we verify that our mixture of hyperfine states is collisionally stable, with no observable inelastic loss.

arXiv:2003.05925Journal of Physics B Atomic Molecular and Optical PhysicsJun 14, 202012 citations

Optical Manipulation of Ultracold Atoms

Gediminas Juzeliūnas, Patrik Öhberg

Elsevier eBooksJan 1, 200811 citations

Experimental Methods of Ultracold Atomic Physics

Dan Stamper-Kurn, Joseph H. Thywissen

arXiv:1111.6196Contemporary concepts of condensed matter scienceJan 1, 20128 citations

Coherent manipulation of ultracold atoms with microwave near-fields

Pascal Böhi

The spectacular progress in the field of ultracold quantum gases is intimately connected with the availability of sophisticated techniques for quantum-level control of internal states, motional states, and collisional interactions. Atom chips provide such control in compact, robust, and scalable setups, which makes them attractive for both applications and fundamental studies. In this thesis I report on experiments that use a new method for coherent manipulation of ultracold atoms. The method is based on microwave near-fields, provided by a waveguide structure that is fully integrated on an atom chip. We generate microwave near-field potentials that combine the versatility of optical traps with the robustness and tailorability of static magnetic microtraps. These potentials depend on the internal atomic state, and we use them for state-selective splitting of Rb Bose-Einstein condensates. We show for the first time combined coherent manipulation of internal and motional states on an atom chip, realizing a trapped-atom interferometer with internal state labeling of the interferometer paths. Moreover, we use microwave near-field potentials for the preparation of spin-squeezed states for quantum-enhanced metrology through controlling state-dependent collisional interactions. In addition, very promising proposals exist for the implementation of a quantum phase gate using these potentials. Measuring microwave fields is important for engineering of microwave devices as well as in science, e.g. to characterize the field homogeneity in the interaction regions of an atomic clock. We develop a novel technique that uses clouds of uncondensed ultracold atoms as sensitive, tunable and non-invasive probes for microwave field imaging with micrometer spatial resolution. The microwave magnetic field components drive Rabi oscillations on atomic hyperfine transitions whose frequency can be tuned with a static magnetic field. Readout is accomplished using state-selective absorption imaging. Quantitative data extraction is simple and it is possible to reconstruct the amplitudes and phases of the different microwave magnetic field components. While we demonstrate 2D imaging, an extension to 3D imaging is straightforward. We use the method to determine the microwave near-field distribution around the on-chip waveguide and reconstruct the corresponding current distribution. For our experimental parameters, the method provides a microwave magnetic field sensitivity of 0.2 mG, which can even be improved further with variants discussed. The experiments presented in this thesis open the path for the realization of portable quantum-enhanced interferometer devices, the implementation of a quantum phase gate as well as for a new generation of microwave field sensors.The spectacular progress in the field of ultracold quantum gases is intimately connected with the availability of sophisticated techniques for quantum-level control of internal states, motional states, and collisional interactions. Atom chips provide such control in compact, robust, and scalable setups, which makes them attractive for both applications and fundamental studies. In this thesis I report on experiments that use a new method for coherent manipulation of ultracold atoms. The method is based on microwave near-fields, provided by a waveguide structure that is fully integrated on an atom chip. We generate microwave near-field potentials that combine the versatility of optical traps with the robustness and tailorability of static magnetic microtraps. These potentials depend on the internal atomic state, and we use them for state-selective splitting of Rb Bose-Einstein condensates. We show for the first time combined coherent manipulation of internal and motional states on an atom chip, realizing a trapped-atom interferometer with internal state labeling of the interferometer paths. Moreover, we use microwave near-field potentials for the preparation of spin-squeezed states for quantum-enhanced metrology through controlling state-dependent collisional interactions. In addition, very promising proposals exist for the implementation of a quantum phase gate using these potentials. Measuring microwave fields is important for engineering of microwave devices as well as in science, e.g. to characterize the field homogeneity in the interaction regions of an atomic clock. We develop a novel technique that uses clouds of uncondensed ultracold atoms as sensitive, tunable and non-invasive probes for microwave field imaging with micrometer spatial resolution. The microwave magnetic field components drive Rabi oscillations on atomic hyperfine transitions whose frequency can be tuned with a static magnetic field. Readout is accomplished using state-selective absorption imaging. Quantitative data extraction is simple and it is possible to reconstruct the amplitudes and phases of the different microwave magnetic field components. While we demonstrate 2D imaging, an extension to 3D imaging is straightforward. We use the method to determine the microwave near-field distribution around the on-chip waveguide and reconstruct the corresponding current distribution. For our experimental parameters, the method provides a microwave magnetic field sensitivity of 0.2 mG, which can even be improved further with variants discussed. The experiments presented in this thesis open the path for the realization of portable quantum-enhanced interferometer devices, the implementation of a quantum phase gate as well as for a new generation of microwave field sensors.

Jan 1, 20104 citations

We report the observation and manipulation of heteronuclear spin dynamics in a spin-1 mixture of ultracold

^{87}\mathrm{Rb}

and

^{23}\mathrm{Na}

atoms. The dynamics is driven by the interspecies spin-dependent interaction and shows a pronounced dependence on magnetic fields with influences from both linear and quadratic Zeeman shifts. Similar to the well-studied homonuclear cases, the interspecies spin dynamics can be controlled by tuning the quadratic Zeeman shift with far-detuned microwave fields. In addition, we successfully realize spin dynamics' control with vector light shifts which act as a species-selective effective magnetic field on

^{87}\mathrm{Rb}

atoms. Both methods show negligible loss of atoms thus will be powerful techniques for investigating spin dynamics with fast temporal and high spatial resolutions.