Real-Space Mapping of Polaritons in 2D Materials

The performance of the next-generation electronic devices based on graphene and other 2D materials is strongly influenced by the structure-function relationship. Scattering-type scanning near-field optical microscopy (s-SNOM) is the ideal technology to investigate such material systems at the nanoscale. s-SNOM combines the best of two worlds: (i) the high spatial resolution of Atomic Force Microscopy (AFM) and (ii) the analytical power of optical microscopy and spectroscopy. Achieving an unmatched spatial resolution below 10 nanometer this technology opens a new era for modern nano-analytical applications such as chemical identification, free-carrier profiling and plasmonic near-field mapping. Recent research highlights on graphene and other 2D materials include contact-free access to the local conductivity, the electron mobility, and the intrinsic electron doping by resolving propagating phonon-, plasmon-, and exciton-polariton directly in space and time. In this presentation we will introduce the basic principles of near-field microscopy for imaging and spectroscopy with 10 nanometer spatial resolution and address their impact and key applications in the field of 2D materials.