Science - USA (2020-03-13)

ACKNOWLEDGMENTS
We thank A. Johnson, P. Knöpfel, G. Martin, and G. Holderied for
technical support.Funding:Funding was provided by the Swiss
National Science Foundation as part of the National Centre of
Competence in Research, Quantum Science and Technology
(NCCR-QSIT), grant CRSII5_183579, and by the University of Basel.
Author contributions:M.S. and Z.M. carried out the experiments

and analyzed the data. K.N. and G.H. contributed to developing

the experimental methodology and setup. S.W. conceived and

supervised the project. All authors contributed to the writing of the

manuscript.Competing interests:The authors declare no

competing interests.Data and materials availability:The raw

data supporting the findings of this study are available at the

Zenodo repository ( 54 ).

SUPPLEMENTARY MATERIALS

science.sciencemag.org/content/367/6483/1213/suppl/DC1

Supplementary Text

Fig. S1

References ( 55 – 62 )

25 October 2019; accepted 31 January 2020

10.1126/science.aaz9837

Sinhalet al.,Science 367 , 1213–1218 (2020) 13 March 2020 6of6

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