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Q: Quantenoptik
Q 17: Poster: Cooling and Trapping
Q 17.1: Poster
Mittwoch, 4. April 2001, 12:30–15:00, AT2
Thermally induced hopping of a pair of trapped ions in a bistable potential — •K. Abich, D. Reiss, W. Neuhauser, and Ch. Wunderlich — Institut für Laser-Physik, Universität Hamburg, Jungiusstr. 9, 20355 Hamburg
Noise activated escape over a potential barrier is a rather ubiquitous phenomenon in physics, chemistry and biology [1]. Electrodynamically trapped ions represent an ideal microscopic system to investigate fundamental questions related to reaction-rate theory that describes these phenomena. We investigate experimentally the rate of exchange of the positions of two 138Ba+ ions caused by thermally activated hopping over a potential barrier as a function of temperature of the two particles. The potential that determines the motion of the ions as well as the temperature set by laser cooling are well characterized. Direct comparison is possible of the measurements on this prototype system and the theoretical predictions with no free parameters.
[1] P. Hänggi, P. Talkner, M. Borkovec, Rev. Mod. Phys. 62, 251 (1990); H. Frauenfelder in Physics of Biological Systems, Springer, Berlin, 1997, p. 29.