Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 35: Poster I

Q 35.9: Poster

Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof

Effects of stochastic noise on dynamical decoupling procedures — Jozsef Zsolt Bernad, •Holger Frydrych, and Gernot Alber — Institut für Angewandte Physik, Technische Universität Darmstadt, D-64289 Darmstadt

Dynamical decoupling is a well-established technique to protect quantum systems from unwanted influences of their environment by exercising active control. It has been used experimentally to drastically increase the lifetime of qubit states in various implementations. The efficiency of different dynamical decoupling schemes defines the lifetime. However, errors in control operations always limit this efficiency. We propose a stochastic model as a possible description of imperfect control pulses and discuss the impact of this kind of error on different decoupling schemes. In the limit of continuous control, i.e. if the number of pulses N → ∞, we derive a stochastic differential equation for the evolution of the density operator of the controlled system and its environment. In the context of this modified time evolution we discuss possibilities of protecting qubit states against environmental noise.