Single qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. While high fidelity single qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been a major challenge due to rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly-driven CNOT gate for electron spins in silicon. Our platform achieves single-qubit rotations with fidelities >99%, as verified by randomized benchmarking. Gate control of the exchange coupling allows a quantum CNOT gate to be implemented with resonant driving in ~200 ns. We use the CNOT gate to generate a Bell state with 75% fidelity, limited by quantum state readout. Our quantum dot device architecture opens the door to multi-qubit algorithms in silicon.
@article{arxiv.1708.03530,
title = {Quantum CNOT Gate for Spins in Silicon},
author = {D. M. Zajac and A. J. Sigillito and M. Russ and F. Borjans and J. M. Taylor and G. Burkard and J. R. Petta},
journal= {arXiv preprint arXiv:1708.03530},
year = {2018}
}