Non-linear Raman scattering intensities in graphene.

We show that the Raman scattering signals of the two dominant Raman bands G and 2D of graphene sensitively depend on the laser intensity in opposite ways. High electronic temperatures reached for pulsed laser excitation lead to an asymmetric Fermi-Dirac distribution at the different optically resonant states contributing to Raman scattering. This results in a partial Pauli blocking of destructively interfering quantum pathways for G band scattering, which is observed as a super-linear increase of the G band intensity with laser power.

Freely Suspended, van der Waals Bound Organic Nanometer-Thin Functional Films: Mechanical and Electronic Characterization.

Determining the electronic properties of nanoscopic, low-dimensional materials free of external influences is key to the discovery and understanding of new physical phenomena. An example is the suspension of graphene, which has allowed access to their intrinsic charge transport properties. Furthermore, suspending thin films enables their application as membranes, sensors, or resonators, as has been explored extensively.