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arXiv · 1711.00754

High-fidelity quantum gates in Si/SiGe double quantum dots

Maximilian Russ·D. M. Zajac·A. J. Sigillito·F. Borjans·J. M. Taylor·J. R. Petta·Guido Burkard
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Abstract

Motivated by recent experiments of Zajac et al. [arXiv:1708.03530], we theoretically describe high-fidelity two-qubit gates using the exchange interaction between the spins in neighboring quantum dots subject to a magnetic field gradient. We use a combination of analytical calculations and numerical simulations to provide the optimal pulse sequences and parameter settings for the gate operation. We present a novel synchronization method which avoids detrimental spin flips during the gate operation and provide details about phase mismatches accumulated during the two-qubit gates which occur due to residual exchange interaction, non-adiabatic pulses, and off-resonant driving. By adjusting the gate times, synchronizing the resonant and off-resonant transitions, and compensating these phase mismatches by phase control, the overall gate fidelity can be increased significantly.

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Maximilian Russ, D. M. Zajac, A. J. Sigillito, F. Borjans, J. M. Taylor, J. R. Petta, Guido Burkard. 2017-11-02. High-fidelity quantum gates in Si/SiGe double quantum dots. https://doi.org/10.1103/physrevb.97.085421

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