Lundi 08 juillet 2013 à 10h30
Auditoire Stueckelberg, Ecole de Physique

Finite-frequency noise of a single-electron emitter: Simple picture and beyond

Michael V. Moskalets, Kharkiv Polytechnic Institute, Ukraine

I present analytical calculations of a finite-frequency noise of a single-electron source for both adiabatic and non-adiabatic emission conditions within the Floquet scattering matrix theory and complement them with a simple and "intuitive" description. Quite generally for the system driven periodically the correlation function depends on two frequencies, $omega$ and $nOmega-omega$, where $n$ is an integer and $Omega$ is the frequency of a drive. The central peak, $n=0$, of the correlation function exists in the stationary case also. The excess part of its magnitude (induced by the drive) admits a simple interpretation in terms of the phase noise rooted in the uncertainty of the emission time of single electrons (and holes). However in the adiabatic regime such an interpretation requires counterintuitive treatment of the emitted state. The side peaks, $n eq 0$, are completely absent in the stationary case. Their existence is entirely due to absorption of energy quanta of a driven field involved into the noise production. Therefore, the corresponding noise can be refereed to as the photon-induce noise. The change of the magnitude of this noise with changing emission regime can be understood with the help of the scattering amplitude of the electronic source. While the frequency dependence in the adiabatic case is puzzling. Until now I have no a simple classical picture for the photon-induced noise.