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HK: Fachverband Physik der Hadronen und Kerne

HK 6: Theorie

HK 6.1: Vortrag

Montag, 12. März 2007, 18:00–18:15, C

Quantum Compilation into Decoherence-Protected Optimised Controls — •Thomas Schulte-Herbrüggen, Andreas Spörl, and Steffen Glaser — Dept. Chemistry, TU-München, 85747 Garching

Quantum compilation lends itself to be tackled as an optimal control problem. Here methods for implementing quantum modules with least amount of dissipation are devised to give best approximations to unitary gates under explicit relaxation. In the widely used Redfield-regime, they are the methods of choice to govern quantum systems within slowly-relaxing subspaces whenever the drift Hamiltonian would otherwise sweep the system through fast-relaxing states of the embedding larger Liouville space. E.g., in a standard model system, OpenGRAPE derived controls give 95% fidelity thus outperforming the 15% obtained by algebraic approaches significantly. Current generalisations to non-Markovian dissipation are included. For quantum compilation in large systems, we provide optimal-control assisted recursive schemes to fight decoherence by substantially faster quantum machine code.

Practical applications and mathematical foundations are discussed. Recent results on local time-reversal will be given in the outlook.