Nonsymmetrized noise in a quantum dot: Interpretation in terms of energy transfer and coherent superposition of scattering paths

TL;DR

This paper investigates nonsymmetrized current noise in a quantum dot, revealing how energy transfer and quantum coherence influence noise characteristics, with implications for understanding quantum transport phenomena.

Contribution

It provides a detailed analysis of nonsymmetrized noise using Green functions, highlighting the role of coherent superpositions of scattering paths in quantum dots.

Findings

Auto- and cross-correlators expressed in terms of transmission amplitude and coefficient

Identification of energy-transfer processes in noise contributions

Conditions for asymmetric auto-correlator values in reservoirs

Abstract

We calculate the nonsymmetrized current noise in a quantum dot connected to two reservoirs by using the non-equilibrium Green function technique. We show that both the current auto-correlator (inside a single reservoir) and the current cross-correlator (between the two reservoirs) are expressed in terms of transmission amplitude and coefficient through the barriers. We identify the different energy-transfer processes involved in each contribution to the auto-correlator, and we highlight the fact that when there are several physical processes, the contribution results from a coherent superposition of scattering paths. Varying the gate and bias voltages, we discuss the profile of the differential Fano factor in light of recent experiments, and we identify the conditions for having a distinct value for the auto-correlator in the left and right reservoirs.