Non-Poissonian ultrashort nanoscale electron pulses*

The statistical character of electron beams used in current technologies, as described by a stream of particles, is random in nature. Using coincidence measurements of femtosecond pulsed electron pairs, we report the observation of sub-Poissonian electron statistics that are non-random due to two-electron Coulomb interactions, and that exhibit an anti-bunching signal of 1 part in 4 [1]. This advancement is a fundamental step towards observing a strongly quantum degenerate electron beam needed for many applications, and in particular electron correlation spectroscopy. [1] Sam Keramati, Will Brunner, T. J. Gay, and Herman Batelaan, Phys. Rev. Lett. 127, 180602 (2021).