About the Authors

Alberto Natali

Affiliation Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands

Roberta Croce

r.croce@vu.nl

Affiliation Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: AN RC. Performed the experiments: AN. Analyzed the data: AN RC. Wrote the paper: AN RC.