Dieter Suter, Universität Dortmund
Abstract
Decoherence is among the biggest obstacles for implementing high-performance quantum computers. Possible measures for reducing decoherence include dynamic decoupling, i.e. sequences of pulses applied to the system to be protected. While all proposed sequences consist of inversion pulses, they differ in the rotation axes of the pulses and in the choice of delays between the pulses. We have experimentally evaluated a number of proposed sequences and analyzed their performance in terms of decoupling efficiency and robustness against experimental imperfections. The results show that, depending on the experimental boundary conditions, decoherence times can be extended by several orders of magnitude by appropriate choice of the decoupling sequence. While decoherence is mostly considered a nuisance that prevents us from implementing large-scale quantum computing, it can also be be used for quantum simulation, such as the emergence of localization in disordered systems.