Publications Gerhard HENDL

2011

D. Naik, A. Trenkwalder, C. Kohstall, F. M. Spiegelhalder, M. Zaccanti, G. Hendl, F. Schreck, R. Grimm, T. Hanna, P. S. Julienne Feshbach resonances in the 6Li-40K Fermi-Fermi mixture: Elastic versus inelastic interactions., Eur. Phys. J. D 65 65 (2011-01-14), http://dx.doi.org/10.1140/epjd/e2010-10591-2 doi:10.1140/epjd/e2010-10591-2
We present a detailed theoretical and experimental study of Feshbach resonances in the 6Li-40K mixture. Particular attention is given to the inelastic scattering properties, which have not been considered before. As an important example, we thoroughly investigate both elastic and inelastic scattering properties of a resonance that occurs near 155 G. Our theoretical predictions based on a coupled channels calculation are found in excellent agreement with the experimental results. We also present theoretical results on the molecular state that underlies the 155G resonance, in particular concerning its lifetime against spontaneous dissociation. We then present a survey of resonances in the system, fully characterizing the corresponding elastic and inelastic scattering properties. This provides the essential information to identify optimum resonances for applications relying on interaction control in this Fermi-Fermi mixture.

F. Spiegelhalder, A. Trenkwalder, D. Naik, G. Kerner, E. Wille, G. Hendl, F. Schreck, R. Grimm All-optical production of a degenerate mixture of 6Li and 40K and creation of heteronuclear molecules, Phys. Rev. A 81 043637 (2010-01-01), http://dx.doi.org/10.1103/PhysRevA.81.043637 doi:10.1103/PhysRevA.81.043637
We present the essential experimental steps of our all-optical approach to prepare a double-degenerate Fermi-Fermi mixture of 6Li and 40K atoms, which then serves as a starting point for molecule formation. We first describe the optimized trap loading procedures, the internal-state preparation of the sample, and the combined evaporative and sympathetic cooling process. We then discuss the preparation of the sample near an interspecies Feshbach resonance, and we demonstrate the formation of heteronuclear molecules by a magnetic field ramp across the resonance.
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F. Spiegelhalder, A. Trenkwalder, D. Naik, G. Hendl, F. Schreck, R. Grimm Collisional stability of 40K immersed in a strongly interacting Fermi gas of 6Li, Phys. Rev. Lett. 103 223203 (2009-11-25), http://dx.doi.org/10.1103/PhysRevLett.103.223203 doi:10.1103/PhysRevLett.103.223203
We investigate the collisional stability of a sample of 40K atoms immersed in a tunable spin mixture of 6Li atoms. In this three-component Fermi-Fermi mixture, we find very low loss rates in a wide range of interactions as long as molecule formation of 6Li is avoided. The stable fermionic mixture with two resonantly interacting spin states of one species together with another species is a promising system for a broad variety of phenomena in few- and many-body quantum physics.
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