Phase-flip probability per nominal d = 90 nm plunger-to-plunger distance for the conventional conveyor and the two-tone conveyor as a function of the applied conveyor frequency. All conveyor amplitudes are set to A = 100 mV, except for the two-tone conveyor amplitudes above 200 MHz, which are set to 120 mV. The need to increase the amplitude can be understood from c . For conveyor frequencies between 100 MHz and 160 MHz, spin coherence in the conventional conveyor is completely lost (see the missing data points). While the underlying reasons for this phenomenon remain unclear, we provide additional comments in Supplementary Note X . The phase-flip probabilities are extracted from the best fit of the exponential decay of Ramsey or Hahn-echo fringes with increasing shuttling distance. A comment on the data analysis can be found in Supplementary Note XVI . The error bars correspond to one standard deviation extracted from the fit.
