About the Authors

Chun Wu

Affiliation Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, United States of America

Joan-Emma Shea

shea@chem.ucsb.edu

Affiliations Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, United States of America, Department of Physics, University of California, Santa Barbara, Santa Barbara, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: CW JES. Performed the experiments: CW. Analyzed the data: CW. Wrote the paper: CW JES.