Optical sensing of fractional quantum Hall effect in graphene

A. Popert, Y. Shimazaki, 2 M. Kroner, K. Watanabe, T. Taniguchi, A. Imamoğlu, and T. Smoleński Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland Center for Emergent Matter Science, RIKEN, Wako, Saitama 351-0198, Japan Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan