Using scanning tunneling microscopy (STM), we have imaged local charge density fluctuations in monolayer graphene. By placing a small gold nanoparticle on the end of the STM tip, a charge sensor is created. By raster scanning the tip over the surface and using Coulomb blockade spectroscopy, we map the local potential on the graphene. We observe a series of electron and hole doped puddles with a characteristic length scale of ∼20 nm. Theoretical calculations for the correlation length of the puddles based on the number of impurities are in agreement with our measurements.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Apr 6 2011|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics