Christian Glattli from CEA Saclay / ENS will talk on What is the photon statistics emitted by the quantum shot noise of coherent conductors?

Time: 16:00

Location: Delft,;Zaal E

In 1928, Nyquist showed that measuring the high frequency equilibrium current noise power of a conductor can be viewed as recording the electromagnetic power emitted toward the circuit used for power detection. Using a Bose-Einstein photon distribution Nyquist derived the famous Johnson-Nyquist formula for the high frequency equilibrium current noise of conductors including the quantum regime. Here the photon statistics, closely associated to the ‘noise’ of the current noise power, is chaotic (or super-Poissonian, as it should for a black body radiation.

Similarly, measuring the non-equilibrium electronic shot noise of a coherent conductor can be viewed as a photon flux emitted from the conductor to the detector. However we may ask whether the photon statistics, also related to the fourth moment of the current noise power, differs from that of a chaotic radiation. Indeed, predictions show that in some regime (one electronic mode transmitted and frequency close to eV/h)the photon statistics can even be non-classical.

After a presentation of quantum shot noise in conductors, we will discuss the photon statistics expected for different conductors. Then we will present experiments on the high frequency shot noise of a Quantum Point Contact and a tunnel junction, as well as the first determination of the statistics of photons emitted by a tunnel junction in the shot noise regime using Hanbury-Brown Twiss photon correlations at 30mK in the 4-8 GHz frequency range.