Magnetically tunable Feshbach resonances are an indispensable tool for experiments with atomic quantum gases. We report on 37 thus far unpublished Feshbach resonances and four further probable Feshbach resonances in spin mixtures of ultracold fermionic $^{40}\mathrm{K}$ with temperatures well below 100 nK. In particular, we locate a broad resonance at $B=389.7\phantom{\rule{0.16em}{0ex}}\text{G}$ with a magnetic width of $26.7\phantom{\rule{0.28em}{0ex}}\text{G}$ . Here $1\phantom{\rule{0.28em}{0ex}}\text{G}={10}^{\ensuremath{-}4}\phantom{\rule{0.16em}{0ex}}\text{T}$. Furthermore, by exciting low-energy spin waves, we demonstrate a means to precisely determine the zero crossing of the scattering length for this broad Feshbach resonance. Our findings allow for further tunability in experiments with ultracold $^{40}\mathrm{K}$ quantum gases.Magnetically tunable Feshbach resonances are an indispensable tool for experiments with atomic quantum gases. We report on 37 thus far unpublished Feshbach resonances and four further probable Feshbach resonances in spin mixtures of ultracold fermionic $^{40}\mathrm{K}$ with temperatures well below 100 nK. In particular, we locate a broad resonance at $B=389.7\phantom{\rule{0.16em}{0ex}}\text{G}$ with a magnetic width of $26.7\phantom{\rule{0.28em}{0ex}}\text{G}$. Here $1\phantom{\rule{0.28em}{0ex}}\text{G}={10}^{\ensuremath{-}4}\phantom{\rule{0.16em}{0ex}}\text{T}$. Furthermore, by exciting low-energy spin waves, we demonstrate a means to precisely determine the zero crossing of the scattering length for this broad Feshbach resonance. Our findings allow for further tunability in experiments with ultracold $^{40}\mathrm{K}$ quantum gases.

arXiv:1701.02085Physical Review AApr 3, 201716 citations

Magnetically Tuned Spin Dynamics Resonance

Jochen Kronjäger, C. Becker, Patrick Navez +2 more

We present the experimental observation of a magnetically tuned resonance phenomenon in the spin mixing dynamics of ultracold atomic gases. In particular, we study the magnetic field dependence of spin conversion in F=2 (87)Rb spinor condensates in the crossover from interaction dominated to quadratic Zeeman dominated dynamics. We discuss the observations in the framework of spin dynamics as well as matter wave four wave mixing. Furthermore, we show that the validity range of the single mode approximation for spin dynamics is significantly extended at high magnetic field.We present the experimental observation of a magnetically tuned resonance phenomenon in the spin mixing dynamics of ultracold atomic gases. In particular, we study the magnetic field dependence of spin conversion in F=2 (87)Rb spinor condensates in the crossover from interaction dominated to quadratic Zeeman dominated dynamics. We discuss the observations in the framework of spin dynamics as well as matter wave four wave mixing. Furthermore, we show that the validity range of the single mode approximation for spin dynamics is significantly extended at high magnetic field.

arXiv:cond-mat/0606046Physical Review LettersSep 12, 200699 citations

Interplay of spin and motional dynamics in ultracold atoms and molecules

Kaden R. A. Hazzard

Bulletin of the American Physical SocietyJun 12, 20150 citations

Collective Spin Behavior in an Ultracold Quantum Gas

Anonymous

PhysicsJul 5, 20180 citations

Coherent spin-mixing dynamics in thermal Rb87 spin-1 and spin-2 gases

Xiaodong He, Bing Zhu, Xiaoke Li +3 more

We study the nonequilibrium coherent spin-mixing dynamics in ferromagnetic spin-1 and antiferromagnetic spin-2 thermal gases of ultracold $^{87}\mathrm{Rb}$ atoms. Long-lasting spin population oscillations with magnetic-field-dependent resonances are observed in both cases. Our observations are well reproduced by Boltzmann equations of the Wigner distribution function. Compared to the equation of motion of spinor Bose-Einstein condensates, the only difference here is a factor-of-2 increase in the spin-dependent interaction, which is confirmed directly in the spin-2 case by measuring the relation between the oscillation amplitude and the sample's density.We study the nonequilibrium coherent spin-mixing dynamics in ferromagnetic spin-1 and antiferromagnetic spin-2 thermal gases of ultracold $^{87}\mathrm{Rb}$ atoms. Long-lasting spin population oscillations with magnetic-field-dependent resonances are observed in both cases. Our observations are well reproduced by Boltzmann equations of the Wigner distribution function. Compared to the equation of motion of spinor Bose-Einstein condensates, the only difference here is a factor-of-2 increase in the spin-dependent interaction, which is confirmed directly in the spin-2 case by measuring the relation between the oscillation amplitude and the sample's density.

arXiv:1503.01171Physical Review AMar 30, 201517 citations

^{40}\mathrm{K}

with temperatures well below 100 nK. In particular, we locate a broad resonance at

B=389.7\phantom{\rule{0.16em}{0ex}}\text{G}

with a magnetic width of

26.7\phantom{\rule{0.28em}{0ex}}\text{G}

. Here $1\phantom{\rule{0.28em}{0ex}}\text{G}={10}^{\ensuremath{-}4}\phantom{\rule{0.16em}{0ex}}\text{T}$. Furthermore, by exciting low-energy spin waves, we demonstrate a means to precisely determine the zero crossing of the scattering length for this broad Feshbach resonance. Our findings allow for further tunability in experiments with ultracold

^{40}\mathrm{K}

quantum gases.

We study the nonequilibrium coherent spin-mixing dynamics in ferromagnetic spin-1 and antiferromagnetic spin-2 thermal gases of ultracold

^{87}\mathrm{Rb}

atoms. Long-lasting spin population oscillations with magnetic-field-dependent resonances are observed in both cases. Our observations are well reproduced by Boltzmann equations of the Wigner distribution function. Compared to the equation of motion of spinor Bose-Einstein condensates, the only difference here is a factor-of-2 increase in the spin-dependent interaction, which is confirmed directly in the spin-2 case by measuring the relation between the oscillation amplitude and the sample's density.