TY - JOUR
T1 - Gate fidelity and coherence of an electron spin in an Si/SiGe quantum dot with micromagnet
AU - Kawakami, Erika
AU - Jullien, Thibaut
AU - Scarlino, Pasquale
AU - Ward, Daniel R.
AU - Savage, Donald E.
AU - Lagally, Max G.
AU - Dobrovitski, Viatcheslav V.
AU - Friesen, Mark
AU - Coppersmith, Susan N.
AU - Eriksson, Mark A.
AU - Vandersypen, Lieven M.K.
PY - 2016/10/18
Y1 - 2016/10/18
N2 - The gate fidelity and the coherence time of a quantum bit (qubit) are important benchmarks for quantum computation. We construct a qubit using a single electron spin in an Si/SiGe quantum dot and control it electrically via an artificial spin-orbit field from a micromagnet. We measure an average single-qubit gate fidelity of ∼99% using randomized benchmarking, which is consistent with dephasing from the slowly evolving nuclear spins in the substrate. The coherence time measured using dynamical decoupling extends up to ∼400 μs for 128 decoupling pulses, with no sign of saturation. We find evidence that the coherence time is limited by noise in the 10-kHz to 1-MHz range, possibly because charge noise affects the spin via the micromagnet gradient. This work shows that an electron spin in an Si/SiGe quantum dot is a good candidate for quantum information processing as well as for a quantum memory, even without isotopic purification.
AB - The gate fidelity and the coherence time of a quantum bit (qubit) are important benchmarks for quantum computation. We construct a qubit using a single electron spin in an Si/SiGe quantum dot and control it electrically via an artificial spin-orbit field from a micromagnet. We measure an average single-qubit gate fidelity of ∼99% using randomized benchmarking, which is consistent with dephasing from the slowly evolving nuclear spins in the substrate. The coherence time measured using dynamical decoupling extends up to ∼400 μs for 128 decoupling pulses, with no sign of saturation. We find evidence that the coherence time is limited by noise in the 10-kHz to 1-MHz range, possibly because charge noise affects the spin via the micromagnet gradient. This work shows that an electron spin in an Si/SiGe quantum dot is a good candidate for quantum information processing as well as for a quantum memory, even without isotopic purification.
KW - Dynamical decoupling
KW - Electron spin
KW - Qubit
KW - Randomized benchmarking
KW - Si/SiGe quantum dot
UR - http://resolver/tudelft.nl/uuid:1746c5e8-c757-42b7-a127-e383272afcc9
UR - http://www.scopus.com/inward/record.url?scp=84991695777&partnerID=8YFLogxK
U2 - 10.1073/pnas.1603251113
DO - 10.1073/pnas.1603251113
M3 - Article
AN - SCOPUS:84991695777
SN - 0027-8424
VL - 113
SP - 11738
EP - 11743
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 42
ER -