About the Authors

Giuseppe Maulucci

Affiliation Istituto di Fisica, Universitá Cattolica S. Cuore, Roma, Italy

Massimiliano Papi

Affiliation Istituto di Fisica, Universitá Cattolica S. Cuore, Roma, Italy

Giuseppe Arcovito

Affiliation Istituto di Fisica, Universitá Cattolica S. Cuore, Roma, Italy

Marco De Spirito

m.despirito@rm.unicatt.it

Affiliation Istituto di Fisica, Universitá Cattolica S. Cuore, Roma, Italy

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: GM MDS. Performed the experiments: GM MP. Analyzed the data: GM MP GA MDS. Contributed reagents/materials/analysis tools: GM MP GA MDS. Wrote the paper: GM MDS.