About the Authors

Maria I. Davidich

Affiliation Institut für Theoretische Physik, Universität Bremen, Bremen, Germany

Stefan Bornholdt

To whom correspondence should be addressed. E-mail: bornholdt@itp.uni-bremen.de

Affiliation Institut für Theoretische Physik, Universität Bremen, Bremen, Germany

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SB MD. Performed the experiments: MD. Wrote the paper: SB MD.