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

*This work is supported by Deutsche Forschungsgemeinschaft through SFB 631 and NSERC Discovery grants

–

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