%0 Journal Article
%A Struck, Tom
%A Hollmann, Arne
%A Schauer, Floyd
%A Fedorets, Olexiy
%A Schmidbauer, Andreas
%A Sawano, Kentarou
%A Riemann, Helge
%A Abrosimov, Nikolay V.
%A Cywiński, Łukasz
%A Bougeard, Dominique
%A Schreiber, Lars
%T Low-frequency spin qubit energy splitting noise in highly purified 28Si/SiGe
%J International journal of tourism sciences
%V 6
%N 1
%@ 2056-6387
%C London
%I Taylor & Francis816513
%M FZJ-2020-05309
%P 40
%D 2020
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000536095000001
%R 10.1038/s41534-020-0276-2
%U https://juser.fz-juelich.de/record/888904