Project A8:
Charged impurities in an ultracold gas of atoms (2010-2017)
Summary
This project proposes studying the fundamental interactions of a few, trapped, laser-cooled ions with a gas of ultracold atoms. This experimentally unexplored terrain offers a multitude of fascinating experiments on the quantum level, ranging from cold collision physics and ultracold chemistry to polaron-like physics, charge mobility experiments, and quantum entanglement of atoms and ions. The planned physics experiments proposed here are the first steps to open this research area and to explore the scientific potential of the ultracold atom-ion system. The interaction potential between a neutral atom and an ion is mainly based on the 1/r4 polarization potential. The neutral atom is electrically polarized and attracted towards the ion in the inhomogeneous electrical field of the ion. This polarization potential is much more long range compared to a 1/r6 van der Waals potential between two neutral atoms. This fact gives rise to scattering lengths which are typically orders of magnitudes larger than for neutral atoms. As a consequence these strong interactions will lead to an interesting regime of strong coupling and strong correlations between the particles. Tuning these interactions in a controlled way and investigating the ensuing many-body and fewbody physics of this system is a main goal of our proposed work.
Project leaders
Prof. Dr. Johannes Hecker Denschlag, Institut für Quantenmaterie, Universität Ulm
Refs & Publications
A. Krükow, A. Mohammadi, A. Härter, J. Hecker Denschlag"Reactive two-body and three-body collisions of Ba+ in an ultracold Rb gas"
Phys. Rev. A 94, 030701(R) (2016); doi: 10.1103/PhysRevA.94.030701
A. Krükow, A. Mohammadi, A. Härter, J. H. Denschlag, J. Pérez-Ríos, C. H. Greene
"Energy scaling of cold atom-atom-ion three-body recombination"
Phys. Rev. Lett. 116, 193201 (2016); doi: 10.1103/PhysRevLett.116.193201
A. Härter and J. Hecker Denschlag
"Cold atom-ion experiments in hybrid traps"
Contemporary Physics 55, 33-45 (2014); doi: 10.1080/00107514.2013.854618
A. Härter, A. Krükow, A. Brunner, and J. Hecker Denschlag
"Long-term drifts of stray electric fields in a Paul trap"
Appl. Phys. B 114, 275-281 (2014); doi: 10.1007/s00340-013-5688-7
A. Härter, A. Krükow, M. Deiß, B. Drews, E. Tiemann, and J. Hecker Denschlag
"Population distribution of product states following three-body recombination in an ultracold atomic gas"
Nature Physics 9, 512-517 (2013); doi: 10.1038/nphys2661
A. Härter, A. Krükow, A. Brunner, and J. Hecker Denschlag
"Minimization of ion micromotion using ultracold atomic probes"
Appl. Phys. Lett. 102, 221115 (2013); doi: 10.1063/1.4809578
A. Härter, A. Krükow, A. Brunner, W. Schnitzler, S. Schmid, and J. Hecker Denschlag
"A single ion as a three-body reaction center in an ultracold atomic gas"
Phys. Rev. Lett. 109, 123201 (2012); doi: 10.1103/PhysRevLett.109.123201
S. Schmid, A. Härter, A. Frisch, S. Hoinka, and J. Hecker Denschlag
"An apparatus for immersing trapped ions into an ultracold gas of neutral atoms"
Rev. Sci. Instrum. 83, 053108 (2012); Virtual Journal of Atomic Quantum Fluids (June 2012); arXiv:1202.2726; doi: 10.1063/1.4718356
S. Schmid, A. Härter, Johannes, and H. Denschlag
"Dynamics of a cold trapped ion in a Bose-Einstein condensate"
Phys. Rev. Lett.105, 133202 (2010); arXiv:1007.4717; doi: 10.1103/PhysRevLett.105.133202