Dynamics of a cold trapped ion in a Bose-Einstein condensate
Auch gedruckt in der BibliothekW: W-H 12.819
FakultätFakultät für Naturwissenschaften
Ressourcen- / MedientypDissertation, Text
Datum der Freischaltung2012-03-19
In this thesis I have investigated the collisions between laser-cooled trapped ions (Ba+ or Rb+) and ultracold neutral atoms (Rb). For this purpose it was necessary to develop a novel hybrid apparatus, where a Bose-Einstein condensation (BEC) apparatus is combined with a Paul trap for single ions. The ultracold atom cloud is produced in a magnetic trap within the BEC apparatus and then transported vertically over a distance of 30 cm using a 1d moving optical lattice. The interaction between the atoms and the ions can be described by a 1/r4 polarization potential. Generally, the atom-ion interaction is stronger and longrange compared to the interaction between two neutral atoms. In our experiments we were able to observe elastic as well as inelastic atom-ion collisions. Elastic scattering was detected by measuring the loss of atoms in the presence of an ion. From this atom loss measurement we could estimate a typical collision energy of about 10 mK and an elastic scattering cross section on the order of 10−14 m2. Inelastic processes are suppressed by a factor 104 to 105 in our experiment. Nevertheless, we were able to show that the dominant inelastic collision channel is the charge transfer reaction Rb + Ba+ → Rb+ + Ba. As a possible application of our apparatus, we have demonstrated that a single ion can be used to probe the density profile of an ultracold atom cloud.
Freie SchlagwörterCold atoms