Imaging coherent electron flow

In this review, results of imaging coherent electron flow through a two-dimensional electron gas (2DEG) are presented. The images show the modal pattern of electron wavefunctions passing through a quantum point contact. At longer distances, unexpected branching of the electron flow is observed due to the small bumps and dips in the potential caused by the donor atoms. Images of the electron flow being bent by an electrostatic prism are also presented. All of the images are decorated by interference fringes spaced by half the Fermi wavelength, which are used to spatially profile the electron density. A technique for imaging the inelastic scattering length in the 2DEG is also demonstrated.