Ultracold He*+Rb mixture experiment
We are working on an ultracold atomic mixture of metastable triplet He (He*) and Rb. Our cooling strategy is based on a dual-species MOT, simultaneous RF- and MW-induced forced evaporative cooling in a quadrupole magnetic trap and transfer to an 1557-nm single beam optical dipole trap. Recently, we have realized the very first ultracold He*+alkali mixture in an optical dipole trap. We will study interspecies Penning ionization and explore interspecies Feshbach resonances.
An ultracold, optically trapped mixture of 87Rb and metastable 4He atoms
Flores, Mishra, Vassen, Knoop, Eur. Phys. J. D 71, 49 (2017) (open access)
Quantum-state-controlled Penning-ionization reactions between ultracold alkali-metal and metastable helium atoms
Flores, Vassen, Knoop, Phys. Rev. A 94, 050701(R) (2016)
Simple method for producing Bose-Einstein condensates of metastable helium using a single beam optical dipole trap
Flores, Mishra, Vassen, Knoop, Appl. Phys. B 121, 391 (2015) (open access) (pdf)
Efficient production of a 87Rb F=2, mF=2 Bose-Einstein condensate in a hybrid trap
Mishra, Flores, Vassen, Knoop, Eur. Phys. J. D 69, 52 (2015) (open access) (pdf)
Ultracold mixtures of metastable He and Rb: scattering lengths from ab initio calculations and thermalization measurements
Knoop, Zuchowski, Kedziera, Mentel, Pachulski, Mishra, Flores, Vassen, Phys. Rev. A 90, 022709 (2014)
February 2016, Lifetime measurements of ultracold mixture in optical dipole trap
Time evolution of He* in the single beam optical dipole trap, both for a He*+Rb mixture that is stable against Penning ionization (h+C), and after flipping the spin of the He* atoms (h+A), showing a dramatic decrease of the trapping lifetime.
November 2015, Our first dual species hybrid trap signal!
TOF signal (He*) and absorption image (Rb) after loading in the hybrid trap together, about 4x104 atoms of each species with a lifetime exceeding 10 seconds. This is the very first ultracold He*+alkali mixture in an optical dipole trap!
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