Heidelberg 2015 – wissenschaftliches Programm
SYEP 2.4: Vortrag
Montag, 23. März 2015, 15:45–16:00, C/gHS
An optically trapped mixture of metastable helium and rubidium — •Adonis Flores, Hari Prasad Mishra, Wim Vassen, and Steven Knoop — LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, The Netherlands
We report on our efforts to realize an ultracold mixture of metastable triplet 4He and 87Rb in an optical dipole trap (ODT). This extreme mass-imbalanced mixture is interesting for investigating the Efimov trimer spectrum, in particular to test its scale invariance . Recently, we have realized a BEC of 87Rb in the F=2, mF=2 hyperfine substate in a hybrid trap , consisting of a quadrupole magnetic field and a single beam ODT. We also obtain thermal clouds of 1×106 atoms below 1 µK in a pure single beam ODT, by ramping down the magnetic field gradient after evaporative cooling in the hybrid trap. We are currently exploring the application of the hybrid trap for metastable He. Previously, we have studied interspecies thermalization in the quadrupole magnetic trap, from which we have obtained a value of the interspecies quartet scattering length, in agreement with ab initio quantum chemistry calculations . Once we have obtained an ultracold mixture in the ODT we will study interspecies Penning ionization for different spin mixtures and search for interspecies Feshbach resonances.
 R. Pires et al., Phys. Rev. Lett. 112, 250404 (2014)
 H. P. Mishra, A. S. Flores, W. Vassen, and S. Knoop, arXiv:1411.7628
 S. Knoop et al., Phys. Rev. A 90, 022709 (2014)