Finite-frequency noise in a non-interacting quantum dot

Redouane Zamoum (1) , M. Lavagna (2) , Adeline Crépieux (3, 4)

1 UMAOB - Université Mohamed Akli Ouelhadj de Bouira
2 GT - Laboratory of Quantum Theory
3 CPT - E6 Nanophysique
4 CPT - Centre de Physique Théorique - UMR 7332

We calculate the non-symmetrized finite-frequency NS-FF noise for a single-level quantum dot connected to reservoirs in the spinless non-interacting case. The calculations are performed within the framework of the Keldysh Green's function formalism in the wide band approximation limit. We establish the general formula for NS-FF noise for any values of temperature, frequency and bias voltage. The electron transfer processes from one to the other reservoir act via the transmission amplitude and transmission coefficient depending on the energy. By taking the symmetrized version of this expression, we show that our result coincides with the expression of the finite frequency noise obtained by Büttiker using the scattering theory. We also give the explicit analytical expression for the NS-FF noise in the zero temperature limit. By performing numerical calculations, we finally discuss the evolution of the NS-FF noise spectrum when varying temperature, dot energy level, and coupling strength to the reservoirs, revealing a large variety of behaviors such as different symmetry properties and changes of sign in the excess noise.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Redouane Zamoum, M. Lavagna, Adeline Crépieux. Finite-frequency noise in a non-interacting quantum dot. Journal of Statistical Mechanics: Theory and Experiment, 2016, Special Issue on Unsolved Problems of Noise in Physics, Biology and Technology, 2016, pp.054013. ⟨10.1088/1742-5468/2016/05/054013⟩. ⟨hal-01257963⟩