Single-Hot-Electron Wave Packets for Quantum Electrical Metrology

In this paper, we demonstrate an application of non-equilibrium electrons in quantum electrical metrology. Our electrons are emitted from clock-controlled semiconductor single-electron pumps, and are isolated in energy and time from other conduction-band electrons in the system. We show that a voltage comparator can be constructed using these electron wave packets, achieving > 10 GHz sampling bandwidth owing to their short (~10 ps) arrival-time distribution. We also show that investigating the energy and time distribution of the electron wave packets helps to understand the pump operation and improve the current quantisation accuracy.