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Authors and Affiliations

1. SLAC National Accelerator Laboratory, Menlo Park, CA, USA

   Yanwen Sun, River Robles, Thomas M. Linker, Ying Chen, David Cesar, Matthieu Chollet, Taran Driver, Vincent Esposito, Carolyn Gee, Veronica Guo, Alex Halavanau, Yoshio Ichii, Haoyuan Li, Kazutaka Nakahara, Alberto Lutman, Sean OTool, Harrison Pasquinilli, Takahiro Sato, Sanghoon Song, Nicholas Sudar, Ydran Willard, Shao-Ci Wu, James P. Cryan, Matthias F. Kling, Agostino Marinelli & Diling Zhu

2. Applied Physics Department, Stanford University, Stanford, CA, USA

   River Robles, Veronica Guo, Sean OTool, Harrison Pasquinilli & Matthias F. Kling

3. Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA

   River Robles, Thomas M. Linker, Shambhu Ghimire, Chance Ornelas-Skarin, Sean OTool, David A. Reis, James P. Cryan, Matthias F. Kling & Agostino Marinelli

4. RIKEN SPring-8 Center, Hyogo, Japan

   Ichiro Inoue, Taito Osaka & Kenji Tamasaku

5. Department of Advanced Materials Science, The University of Tokyo, Chiba, Japan

   Ichiro Inoue

6. Physics Department, McGill University, Montreal, Quebec, Canada

   Mark Sutton

7. Physics Department, Stanford University, Stanford, CA, USA

   Shao-Ci Wu

Contributions

Y.S., H.L., A.M. and D.Z. conceived the concept. Y.C. and Y.S. designed and modelled the full optical setup using CAD. Y.S., R.R., T.M.L., Y.C., M.C., T.D., S.G., Y.I., I.I., H.L., K.N., T.O., D.A.R., T.S., S.S., M.S., K.T., Y.W., J.P.C., M.F.K., A.M. and D.Z. designed and performed the experiment. R.R., D.C., V.G., A.H., A.L. and N.S. coordinated the hard X-ray attosecond beam delivery. Y.S., R.R., T.M.L., C.O.-S., H.P., M.S. and S.-C.W. analysed the experimental data. V.E. and C.G. provided support for beamline control and analysis software. R.R. and S.O.T. performed supporting FEL simulations. Y.S., R.R., A.M. and D.Z. wrote the manuscript with input from all the other authors.

Corresponding authors

Correspondence to Agostino Marinelli or Diling Zhu.

Competing interests

The authors declare no competing interests.

Peer review information

Nature thanks Balázs Major, Johan Mauritsson and Martin Schultze for their contribution to the peer review of this work. Peer reviewer reports are available.

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