Berlin 2001 – scientific programme
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Q: Quantenoptik
Q 4: Quantum Information I
Q 4.1: Talk
Monday, April 2, 2001, 15:45–16:00, Audimax
Sympathetic cooling of an indium-magnesium ion chain — •Steffen Köhler, Volker Ludsteck, Sang-Kyung Choi, Wolfgang Lange, and Herbert Walther — Max-Planck-Institut für Quantenoptik, Garching, Germany
In a linear ion trap, quantum information may be exchanged between different ions via their vibrational motion. An essential prerequisite is that the motional degrees of freedom are close to the quantum mechanical ground state. An efficient cooling method is required, in particular to realize large scale systems.
We have proposed a method based on the sympathetic cooling effect provided by ions of a different species embedded in the ion chain. An ideally suited candidate for cooling is 115In+, since it offers a transition narrow enough for resolved sideband cooling but strong enough for a high cooling rate [1]. In our experiment, two hyperfine ground states of 25Mg+ ions will be used as the carriers of quantum information. Sympathetic cooling in a heterogeneous (Mg-In) chain has the advantage that the electronic states of the magnesium ions are not affected by the cooling laser, so that continuous cooling is possible. Thus the impact of vibrational decoherence is expected to be significantly reduced.
We present investigations of the formation and stability of magnesium-indium ion chains in a linear trap geometry and discuss their application to quantum information processing.
[1] E. Peik, J. Abel, Th. Becker, J. von Zanthier, H. Walther, Phys. Rev. A 60, 439 (1999).