title: Keeping a quantum bit alive by optimized pi-pulse sequences.
abstract: A general strategy to maintain the coherence of a quantum bit is proposed. The analytical result is derived rigorously including all memory and backaction effects. It is based on an optimized pi-pulse sequence for dynamic decoupling extending the Carr-Purcell-Meiboom-Gill cycle. The optimized sequence is very efficient, in particular, for strong couplings to the environment.
authors.affiliation: Lehrstuhl für Theoretische Physik I, Universität Dortmund, Otto-Hahn Strasse 4, 44221 Dortmund, Germany. goetz.uhrig@uni-dortmund.de
authors.forename: Götz S
authors.initials: GS
authors.lastname: Uhrig