Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 9: Transport: Quantum Coherence and Quantum Information Systems

TT 9.7: Vortrag

Montag, 25. Februar 2008, 15:45–16:00, H 2053

Exact Results on Dynamic Decoupling by π-Pulses in Quantum Information Processes — •Götz S. Uhrig — Lehrstuhl für Theoretische Physik I, TU Dortmund, 44221 Dortmund

The aim of dynamic decoupling consists in the suppression of decoherence by appropriate coherent control of a quantum register. Effectively, the interaction with the environment is reduced and hence the decoherence rate. In particular, a sequence of π-pulses is considered. Here we present exact results on the suppression of the coupling of a quantum bit to its environment by optimized sequences of π-pulses along the storage time t. The more pulses are used the higher is the order in t in which decoherence occurs [1]. To which extent the optimization pays is discussed for different high-energy cutoffs. We show that the results for a spin-boson model hold generally for any kind of bath.

[1] G.S. Uhrig, PRL 98, 100504 (2007)