Study Molecules on Graphene by Low Temperature Scanning Tunneling Microscopy
There are three parts of this talk. First I will introduce step by step how to build one low noise Scanning Tunneling Microscopy (STM) system, particularly for optical experiments. Many details were considered to minimize the noise level of the system. Then I will talk about some experiments on the epitaxial graphene grown on Ru(0001) surface. Periodic Moiré pattern is formed on graphene surface due to the lattice mismatch between graphene and substrate.
The graphene Moiré pattern is periodically corrugated and electronically inhomogeneous as characterized by STM spectroscopy. Electrons and Phonons are localized on the surface. Physical and dynamic properties of molecules on graphene Moiré surface were investigated by both experiments and calculations. In order to continue the low temperature experiments, a lab based liquid Helium recovery facility was built. The homemade facility is performing better than the commercial ones and saving tons of liquid Helium for the lab every year.