Journal Article

PreJuSER-20143

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Symmetry-enhanced performance of dynamical decoupling

Pasini, S.FZJ* ; Uhrig, G. S.

2011
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/11167  doi:10.1103/PhysRevA.84.042336

Abstract: We consider a system with general decoherence and a quadratic dynamical decoupling sequence (QDD) for the coherence control of a qubit coupled to a bath of spins. We investigate the influence of the geometry and of the initial conditions of the bath on the performance of the sequence. The overall performance is quantified by a distance norm d. It is expected that d scales with tau, the total duration of the sequence, as tau(min{Nx, Nz}+1), where N-x and N-z are the number of pulses of the outer and of the inner sequence, respectively. We show both numerically and analytically that the state of the bath can boost the performance of QDD under certain conditions: The scaling of QDD for a given number of pulses can be enhanced by a factor of 2 if the bath is prepared in a highly symmetric state and if the system Hamiltonian is SU(2) invariant.

Keyword(s): J

Note: We would like to thank Gregory Quiroz and Daniel A. Lidar for helpful discussions. The financial support by the grant UH 90/5-1 of the DFG is gratefully acknowledged.

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Contributing Institute(s):

1. Neutronenstreuung (ICS-1)
2. Projekt Europäische Spallationsquelle (international) (ESS)
3. Neutronenstreuung (JCNS-1)

Research Program(s):

1. BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung (P45)
2. Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) (P55)

Appears in the scientific report 2011

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