Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 8: Cooling and Trapping I (joint session A and Q)
A 8.3: Vortrag
Dienstag, 3. April 2001, 16:15–16:30, H104
Laser cooling and heating of two trapped 138Ba+ ions — •D. Reiß, K. Abich, W. Neuhauser, Ch. Wunderlich, and P. E. Toschek — Institut für Laser-Physik, Universität Hamburg, Jungiusstr. 9, 20355 Hamburg
Laser cooling is an essential tool for quantum information processing in ion traps, and it is desirable to have robust cooling techniques at hand that are suited to reach small vibrational quantum numbers at moderate technological expenditure on the side of the laser sources. We study the collective vibrational motion of two trapped 138Ba+ ions cooled by laser light close to the resonances corresponding to the S1/2-P1/2 (493 nm) and P1/2-D3/2 (649 nm) transition, respectively [1]. The motional state of the ions is monitored using a spatially resolving photo multiplier. Depending on the parameter settings (detuning and intensity) of the cooling lasers, distinctively different motional states corresponding to different temperatures are observed. On the other hand the expected temperature can be derived from detailed numerical calculations of laser cooling taking into account the Zeeman structure of the energy levels involved [2]. Parameter regimes of the laser light are identified that imply most efficient laser cooling.
[1] B. Appasamy, Y. Stalgies, and P. E. Toschek, Phys. Rev. Lett. 80, (1998).
[2] D. Reiß, A. Lindner, and R. Blatt, Phys. Rev. A 54, 5133 (1998).