Optimal Control of a Qubit coupled to a Two-Level Fluctuator

ORAL

Abstract

Experimental realizations of superconducting qubits are prone to decoherence from a fluctuating environment. An important source of charge and critical current noise are two-level fluctuators with a Lorentzian noise spectrum. We apply a recent generalization of quantum optimal control in presence of decoherence, the openGRAPE algorithm [1], to a microscopic model of a qubit coupled to a single two-level fluctuator. We find pulses that decrease the error of single qubit quantum gates and quantum memory up to a magnitude compared with conventional pulses. The qubit is pulsed in a way that the effect of the fluctuator is minimized. We investigate system and optimized pulses in various parameter regimes. [1] T. Schulte-Herbr\"uggen et al., quant-ph/0609037

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Authors

  • Patrick Rebentrost

    IQC and Physics Department, University of Waterloo and Ludwig-Maximilians-University, Munich

  • Ioana Serban

    IQC and Physics Department, University of Waterloo and Ludwig-Maximilians-University, Munich, Institute for Quantum Computing, Waterloo, Canada and Ludwig-Maximilians-Universitaet Munich, Germany

  • Frank Wilhelm

    IQC and Physics Department, University of Waterloo, IQC and Physics Department, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada, Institute for Quantum Computing, University of Waterloo, Ontario, Canada, Institute for Quantum Computing, Waterloo, Canada, University of Waterloo

  • Thomas Schulte-Herbr\"uggen

    Technical University Munich