About the Authors

Michael Welter

Affiliation Theoretical Physics, Saarland University, Saarbrücken, Germany

Heiko Rieger

h.rieger@mx.uni-saarland.de

Affiliation Theoretical Physics, Saarland University, Saarbrücken, Germany

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: MW HR. Performed the experiments: MW. Analyzed the data: MW. Wrote the paper: MW HR.