1. Department of Physics, University of Colorado, Boulder, CO 80309, USA.
2. PULS Group, Department of Physics and Cluster of Excellence: Engineering of Advanced Materials, Friedrich-Alexander University Erlangen-Nurnberg, Nagelsbachstr. 49b, Erlangen, Germany.
3. Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.