2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009;
Pittsburgh, Pennsylvania
Session Q16: Focus Session: Dipolar Gases and Ultra-Cold Molecules
11:15 AM–2:15 PM,
Wednesday, March 18, 2009
Room: 317
Sponsoring
Unit:
DAMOP
Chair: Dan Stamper-Kurn, University of California, Berkeley
Abstract ID: BAPS.2009.MAR.Q16.2
Abstract: Q16.00002 : Ultracold Heteronuclear Fermi-Fermi Molecules
11:51 AM–12:27 PM
Preview Abstract
Abstract
Author:
Kai Dieckmann
(Ludwig-Maximilians-University of Munich, Germany)
Spin mixtures of quantum-degenerate fermionic gases exhibit long
lifetimes
in the strongly-interacting regime near a Feshbach resonance.
This has
opened the door for numerous key experiments like the creation of
Fermi-Fermi molecules, the realization of molecular BEC, the
observation of
a pairing gap and of superfluidity in a fermionic gas in the BEC-BCS
cross-over region near a Feshbach resonance.
We present the production of $^{6}$Li-$^{40}$K heteronuclear
molecules based
on our experimental platform for the production of a two-species
mixture of
quantum-degenerate Fermi gases.
Our production scheme for quantum-degenerate fermionic $^{6}$Li
and $^{40}$K
and bosonic $^{87}$Rb gases is based on multiple species
magneto-optical
trapping [1] and sympathetic cooling of the fermions by rubidium. We
demonstrated catalytic cooling of lithium by potassium,
overcoming the small
lithium rubidium cross section. We achieved to simultaneously
enter quantum
degeneracy for all three species [2] with lowest temperatures of
0.25 and
0.35 times the Fermi temperature for lithium and potassium at
about 260 nK.
The highest atom numbers achieved are 1.8x10$^{5}$ for lithium as
well as
potassium, and about 1x10$^{5}$ for rubidium.
We studied two s-wave Feshbach resonances between lithium and
potassium [3]
at 155 G and 168 G. By magnetic field sweeps we created about
4$\cdot
$10$^{4 6}$Li-$^{40}$K molecules at conversion efficiencies of up
to 50 {\%}
[4]. With a Stern-Gerlach purification technique we are able to
image
molecules and atoms spatially separated from each other. We
discuss the
lifetime of the molecule-atom mixture close to resonance.
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References:
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[1] M.Taglieber, A.-C.Voigt, F.Henkel, S.Fray, T.W.H\"{a}nsch,
and K. Dieckmann, Phys. Rev. A 73, 011402(R) (2006)\\[0pt]
[2] M. Taglieber, A.-C. Voigt, T. Aoki, T. W. H\"{a}nsch, and K.
Dieckmann, Phys. Rev. Lett., 100, 010401, (2008)\\[0pt]
[3] E.Wille, et al., PRL, 100,053201,(2008)\\[0pt]
[4] A.-C. Voigt, M. Taglieber, L. Costa, T. Aoki, W. Wieser, T.W.
Haensch, and K. Dieckmann, accepted for publication in Phys. Rev.
Lett.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.Q16.2