Giant enhancement of third-harmonic generation in graphene–metal heterostructures

Irati Alonso Calafell, Lee A. Rozema, David Alcaraz Iranzo, Alessandro Trenti, Philipp K. Jenke, Joel D. Cox, Avinash Kumar, H. Bieliaiev, Sébastien Nanot, Cheng Peng, Dmitri K. Efetov, Jin‐Yong Hong, Jing Kong, Dirk Englund, F. Javier Garcı́a de Abajo, Frank H. L. Koppens, Philip Walther