# Experimental Test of the High-Frequency Quantum Shot Noise Theory in a Quantum Point Contact

## TL;DR

This study presents direct measurements of high-frequency shot noise in a quantum point contact, confirming the quantum shot noise scattering theory without adjustable parameters at frequencies 4-8 GHz.

## Contribution

It provides the first complete experimental validation of finite frequency shot noise theory in quantum point contacts with no adjustable parameters.

## Key findings

- Shot noise suppression observed when Vds < hν/e
- Measurements match theoretical predictions precisely
- First experimental test of the theory at GHz frequencies

## Abstract

We report on direct measurements of the electronic shot noise of a quantum point contact at frequencies nu 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 quantum point contact drain-source voltage Vds are comparable to the photon energy hnu leading to observation of the shot noise suppression when $V_{ds}<h\nu/e$. Our measurements provide the first complete test of the finite frequency shot noise scattering theory without adjustable parameters.