Cooled scanning probe microscope to image electronic interactions in graphene

Scanning probe techniques such as scanning SQUID, diamond nitrogen-vacanacy magnetometry and Scanning Gate Microscopes (SGM) have revealed spatial distribution of electronic behavior indicating laminar Poiseuille flow in graphene, vortex sheets in WTe2, insulating and superconducting states in twisted bilayer graphene (tBLGs), viscous flow in GaAs heterostructures. However, a direct imaging of electron interaction and spatial features such as whirlpools, eddies, vortex sheets and insulating localized states in electronic flow in graphene is yet to be observed. In this talk, I will present our work on directly imaging such behavior of electrons in graphene. We propose to use combination of scanning NV center diamond magnetometry and scanning gate microscopy to image carrier collisions in graphene to explore the role they place in the Dirac fluid, Fermi liquid, and hydrodynamic flow regimes. We present our progress in building the apparatus, fabricating graphene devices and preliminary transport measurements on graphene devices. In our imaging experiment, we anticipate directly observing electrons, hydrodynamic effects such as whirlpools and vortex sheets in electron flow, and localized states related to Mott-like insulator in tBLG.