Nanophysics Seminar

Prof. Dimitri N. Basov, Columbia University, New York, USA
Photonic Crystals for Nano-Light in Twisted Bilayer Graphene

Graphene is an atomically thin plasmonic medium that supports highly confined plasmon polaritons, or nano-light, with very low loss. Electronic properties of graphene can be drastically altered when it is laid upon another graphene layer, resulting in a moiré superlattice. The relative twist angle between the two layers is a key tuning parameter of the interlayer coupling in thus obtained twisted bilayer graphene (TBG). We studied propagation of plasmon polaritons in TBG by infrared nano-imaging. We discovered that the atomic reconstruction occurring at small twist angles turns the TBG into a natural plasmon photonic crystal for propagating nano-light. This discovery points to a pathway towards controlling nano-light by exploiting quantum properties of graphene and other atomically layered van der Waals materials instead of arduous top-down nanofabrication. (To appear in Science 2019).

Thursday, 29.11.18

11:30 h - 12:30 h

Geschwister-Scholl-Platz 1