  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.
This advancement is a fundamental step towards realizing a strongly quantum
degenerate electron beam needed for many applications, and in particular
electron correlation spectroscopy.
