01279nas a2200181 4500008004100000245009100041210006900132260001400201490000700215520071200222100002000934700002000954700001900974700002500993700002301018700001901041856003701060 2011 eng d00aSpatial separation in a thermal mixture of ultracold $^{174}$Yb and $^{87}$Rb atoms
0 aSpatial separation in a thermal mixture of ultracold 174 Yb and c2011/4/210 v833 a We report on the observation of unusually strong interactions in a thermal
mixture of ultracold atoms which cause a significant modification of the
spatial distribution. A mixture of $^{87}$Rb and $^{174}$Yb with a temperature
of a few $\mu$K is prepared in a hybrid trap consisting of a bichromatic
optical potential superimposed on a magnetic trap. For suitable trap parameters
and temperatures, a spatial separation of the two species is observed. We infer
that the separation is driven by a large interaction strength between
$^{174}$Yb and $^{87}$Rb accompanied by a large three-body recombination rate.
Based on this assumption we have developed a diffusion model which reproduces
our observations.
1 aBaumer, Florian1 aMünchow, Frank1 aGörlitz, Axel1 aMaxwell, Stephen, E.1 aJulienne, Paul, S.1 aTiesinga, Eite uhttp://arxiv.org/abs/1104.1722v101306nas a2200181 4500008004100000245007600041210006900117260001300186490000800199520075700207100001700964700001900981700002501000700002401025700001901049700001901068856003701087 2009 eng d00aNumber Fluctuations and Energy Dissipation in Sodium Spinor Condensates0 aNumber Fluctuations and Energy Dissipation in Sodium Spinor Cond c2009/6/50 v1023 a We characterize fluctuations in atom number and spin populations in F=1
sodium spinor condensates. We find that the fluctuations enable a quantitative
measure of energy dissipation in the condensate. The time evolution of the
population fluctuations shows a maximum. We interpret this as evidence of a
dissipation-driven separatrix crossing in phase space. For a given initial
state, the critical time to the separatrix crossing is found to depend
exponentially on the magnetic field and linearly on condensate density. This
crossing is confirmed by tracking the energy of the spinor condensate as well
as by Faraday rotation spectroscopy. We also introduce a phenomenological model
that describes the observed dissipation with a single coefficient.
1 aLiu, Yingmei1 aGomez, Eduardo1 aMaxwell, Stephen, E.1 aTurner, Lincoln, D.1 aTiesinga, Eite1 aLett, Paul, D. uhttp://arxiv.org/abs/0906.2110v101274nas a2200181 4500008004100000245011400041210006900155260001400224490000800238520068400246100001700930700002000947700002500967700002400992700001901016700002001035856003701055 2009 eng d00aQuantum Phase Transitions and Continuous Observation of Spinor Dynamics in an Antiferromagnetic Condensate
0 aQuantum Phase Transitions and Continuous Observation of Spinor D c2009/3/230 v1023 a Condensates of spin-1 sodium display rich spin dynamics due to the
antiferromagnetic nature of the interactions in this system. We use Faraday
rotation spectroscopy to make a continuous and minimally destructive
measurement of the dynamics over multiple spin oscillations on a single
evolving condensate. This method provides a sharp signature to locate a
magnetically tuned separatrix in phase space which depends on the net
magnetization. We also observe a phase transition from a two- to a
three-component condensate at a low but finite temperature using a
Stern-Gerlach imaging technique. This transition should be preserved as a
zero-temperature quantum phase transition.
1 aLiu, Yingmei1 aJung, Sebastian1 aMaxwell, Stephen, E.1 aTurner, Lincoln, D.1 aTiesinga, Eite1 aLett, Paul., D. uhttp://arxiv.org/abs/0902.3189v1