High frequency shot noise of phase coherent conductors

We report on direct measurements of the electronic shot noise of a Quantum Point Contact (QPC) at frequencies ν in the range 4–8 GHz. The very small energy scale used ensures energy independent transmissions of the few transmitted electronic modes and their accurate knowledge. Both the thermal energy and the QPC drain‐source voltage Vds are comparable to the photon energy leading to the observation of the shot noise suppression when Vds