Emission noise in an interacting quantum dot with asymmetrical barriers
The emission noise through a quantum dot is calculated at frequency $\nu$ in the presence of Coulomb interaction in the dot and barrier asymmetry between the dot and two metallic reservoirs. The calculation is performed on the basis of a method which consists in identifying the transmission processes of one electron-hole pair through the dot, where its recombination leads to the emission of an energy $h\nu$ in one of the reservoirs. This method allows us to get the expressions for the auto-correlator and the cross-correlator noises, which are found to be in full agreement with the ones derived by using more complicated approaches. Upon the application of a voltage bias $V$, we find that the noise derivative, $dS_{\alpha\alpha}(\nu)/dV$, is zero as long as $|eV|<h\nu$ whatever the strength of the interaction is. When the system is in the Kondo regime, $dS_{\alpha\alpha}(\nu)/dV$ exhibits Kondo peaks in addition to broad peaks located at the boundaries of the Coulomb blockade structure. The whole results explain the recent emission noise measurements in a carbon nanotube dot in the Kondo regime.