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arXiv:quant-ph/0509125 · Physical Review Letters

Feedback Cooling of a Single Trapped Ion

Pavel A. Bushev, D. Rotter, Alex Wilson, François Dubin, Christoph Becher, Jürgen Eschner, R. Blatt, Viktor Steixner, Peter Rabl, P. Zoller

Published Feb 3, 2006• 200 citations
arXivHTMLPDF

Abstract

Based on a real-time measurement of the motion of a single ion in a Paul trap, we demonstrate its electromechanical cooling below the Doppler limit by homodyne feedback control (cold damping). The feedback cooling results are well described by a model based on a quantum mechanical master equation.
DOI
10.1103/physrevlett.96.043003

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We present a sub-Doppler cooling scheme of a two-trapped-ion crystal by quantum feedback control method. In the scheme, we obtain the motional information by continuously measuring the spontaneous emission photons from one single ion of the crystal, and then apply a feedback force to cool the whole chain down.We derive the cooling dynamics of the cooling scheme using quantum feedback theory and quantum regression theorem. The result shows that with experimentally achievable parameters, our scheme can achieve lower temperature and faster cooling rate than Doppler cooling.
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