Tailored Single-Atom Collisions at Ultralow Energies

Autor: Daniel Adam, Eberhard Tiemann, Felix Schmidt, Tobias Lausch, Artur Widera, Quentin Bouton, Jens Nettersheim, Daniel Mayer
Rok vydání: 2019
Předmět:
Zdroj: Web of Science
ISSN: 1079-7114
0031-9007
Popis: We employ collisions of individual atomic cesium (Cs) impurities with an ultracold rubidium (Rb) gas to probe atomic interaction with hyperfine- and Zeeman-state sensitivity. Controlling the Rb bath's internal state yields access to novel phenomena observed in inter-atomic spin-exchange. These can be tailored at ultra-low energies, owing to the excellent experimental control over all relevant energy scales. First, detecting spin-exchange dynamics in the Cs hyperfine state manifold, we resolve a series of previously unreported Feshbach resonances at magnetic fields below 300 mG, separated by energies as low as $h\times 15$ kHz. The series originates from a coupling to molecular states with binding energies below $h\times 1$ kHz and wave function extensions in the micrometer range. Second, at magnetic fields below $\approx 100\,$mG, we observe the emergence of a new reaction path for alkali atoms, where in a single, direct collision between two atoms two quanta of angular momentum can be transferred. This path originates from the hyperfine-analogue of dipolar spin-spin relaxation. Our work yields control of subtle ultra-low-energy features of atomic collision dynamics, opening new routes for advanced state-to-state chemistry, for controlling spin-exchange in quantum many-body systems for solid state simulations, or for determination of high-precision molecular potentials.
Comment: 5 pages, 4 figures, supplementary material
Databáze: OpenAIRE
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