Image of a Single Electron Quantum Dot
R.M. Westervelt, E.J. Heller, and A.C. Gossard
Image of a GaAs quantum dot that contains just one electron, taken with a liquid-He cooled scanning probe microscope. The color scale shows the change in dot conductance in the Coulomb blockade regime as the SPM tip scanned above. When the charged tip moves inside the ring, it pushes the last electron off the dot.