TY  - JOUR
AU  - Struck, Tom
AU  - Hollmann, Arne
AU  - Schauer, Floyd
AU  - Fedorets, Olexiy
AU  - Schmidbauer, Andreas
AU  - Sawano, Kentarou
AU  - Riemann, Helge
AU  - Abrosimov, Nikolay V.
AU  - Cywiński, Łukasz
AU  - Bougeard, Dominique
AU  - Schreiber, Lars
TI  - Low-frequency spin qubit energy splitting noise in highly purified 28Si/SiGe
JO  - International journal of tourism sciences
VL  - 6
IS  - 1
SN  - 2056-6387
CY  - London
PB  - Taylor & Francis816513
M1  - FZJ-2020-05309
SP  - 40
PY  - 2020
AB  - We identify the dominant source for low-frequency spin qubit splitting noise in a highly isotopically-purified silicon device with an embedded nanomagnet and a spin echo decay time Techo2 = 128 µs. The power spectral density (PSD) of the charge noise explains both, the clear transition from a 1/f2- to a 1/f-dependence of the splitting noise PSD as well as the experimental observation of a decreasing time-ensemble spin dephasing time, from T∗2≈ 20 µs, with increasing measurement time over several hours. Despite their strong hyperfine contact interaction, the few 73Ge nuclei overlapping with the quantum dot in the barrier do not limit T∗2, likely because their dynamics is frozen on a few hours measurement scale. We conclude that charge noise and the design of the gradient magnetic field are the key to further improve the qubit fidelity in isotopically purified 28Si/SiGe.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000536095000001
DO  - DOI:10.1038/s41534-020-0276-2
UR  - https://juser.fz-juelich.de/record/888904
ER  -