Near-field photocurrent nanoscopy on bare and encapsulated graphene

Achim Woessner, Pablo Alonso-González, Mark B. Lundeberg, Yuanda Gao, Jose E. Barrios-Vargas, Gabriele Navickaite, Qiong Ma, Davide Janner, Kenji Watanabe, Aron W. Cummings, Takashi Taniguchi, Valerio Pruneri, Stephan Roche, Pablo Jarillo-Herrero, James Hone, Rainer Hillenbrand, Frank H.L. Koppens