%0 Journal Article %J Physical Review B %D 2018 %T High-fidelity quantum gates in Si/SiGe double quantum dots %A Maximilian Russ %A D. M. Zajac %A A. J. Sigillito %A F. Borjans %A J. M. Taylor %A J. R. Petta %A Guido Burkard %X

Motivated by recent experiments of Zajac et al. [Science 359, 439 (2018)], 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 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, nonadiabatic 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.

%B Physical Review B %V 97 %P 085421 %8 2018/02/15 %G eng %U https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.085421 %N 8 %R 10.1103/PhysRevB.97.085421