Fermi Condensates

Ultracold atomic gases have proven to be remarkable model systems for exploring quantum mechanical phenomena. Experimental work on gases of fermionic atoms in particular has seen large recent progress including the attainment of so-called Fermi condensates. In this article we will discuss this recent development and the unique control over interparticle interactions that made it possible.Comment: Proceedings of ICAP-2004 (Rio de Janeiro). Review of Potassium experiment at JILA, Boulder, C

Cooling a single atom in an optical tweezer to its quantum ground state

We report cooling of a single neutral atom to its three-dimensional vibrational ground state in an optical tweezer. After employing Raman sideband cooling for tens of milliseconds, we measure via sideband spectroscopy a three-dimensional ground-state occupation of ~90%. We further observe coherent control of the spin and motional state of the trapped atom. Our demonstration shows that an optical tweezer, formed simply by a tightly focused beam of light, creates sufficient confinement for efficient sideband cooling. This source of ground-state neutral atoms will be instrumental in numerous quantum simulation and logic applications that require a versatile platform for storing and manipulating ultracold single neutral atoms. For example, these results will improve current optical tweezer experiments studying atom-photon coupling and Rydberg quantum logic gates, and could provide new opportunities such as rapid production of single dipolar molecules or quantum simulation in tweezer arrays.Comment: Updated intro, titl

Population mixing due to dipole-dipole interactions in a 1D array of multilevel atoms

We examine theoretically how dipole-dipole interactions arising from multiple photon scattering lead to a modified distribution of ground state populations in a driven, ordered 1D array of multilevel atoms. Specifically, we devise a level configuration in which a ground-state population accumulated due solely to dipole-dipole interactions can be up to 20\% in regimes accessible to current experiments with neutral atom arrays. For much larger systems, the steady state can consist of an equal distribution of population across the ground state manifold. Our results illustrate how dipole-dipole interactions can be accentuated through interference, and regulated by the geometry of ordered atom arrays. More generally, control techniques for multilevel atoms that can be degraded by multiple scattering, such as optical pumping, will benefit from an improved understanding and control of dipole-dipole interactions available in ordered arrays.Comment: paper is now identical to published versio

Correcting heading errors in optically pumped magnetometers through microwave interrogation

We demonstrate how to measure in-situ for heading errors of optically pumped magnetometers in geomagnetic fields. For this, we implement microwave-driven Rabi oscillations and Ramsey interferometry on hyperfine transitions as two independent methods to detect scalar systematics of free induction decay (FID) signals. We showcase the wide applicability of this technique by operating in the challenging parameter regime of compact vapor cells with imperfect pumping and high buffer gas pressure. In this system, we achieve suppression of large inaccuracies arising from nonlinear Zeeman (NLZ) shifts by up to a factor of 10 to levels below 0.6 nT. In the Ramsey method we accomplish this, even in arbitrary magnetic field directions, by employing a hyper-Ramsey protocol and optical pumping with adiabatic power ramps. For the Rabi technique, this level of accuracy is reached, despite associated drive-dependent shifts, by referencing Rabi frequency measurements to a complete atom-microwave coupling model that incorporates the microwave polarization structure.Comment: 6 pages, 4 figures + supplementary 16 pages, 10 figure

Single atom trapping in a metasurface lens optical tweezer

Optical metasurfaces of sub-wavelength pillars have provided new capabilities for the versatile definition of the amplitude, phase, and polarization of light. In this work we demonstrate that an efficient dielectric metasurface lens can be used to trap and image single neutral atoms. We characterize the high numerical aperture optical tweezers using the trapped atoms and compare to numerical computations of the metasurface lens performance. We predict future metasurfaces for atom trapping can leverage multiple ongoing developments in metasurface design and enable multifunctional control in complex experiments with neutral-atoms arrays.Comment: 9 pages, 5 figure