Thermal Electron Wave Packets
E.J. Heller and R.M. Westervelt

A thermal wave packet (whose energy distribution is derived from its temperature) is shown emerging from a small opening (a quantum point contact, or QPC) from which is spreads out, hitting impurities. These scatter the waves, some of which head back to the QPC. They can interfere there to produce interference fringes in an image of electron flow only if they arrive at the same time.