Strongly correlated charge transport in silicon MOSFET quantum dots

TL;DR

This study uses high-sensitivity shot noise measurements in silicon MOSFET quantum dots to explore charge transfer dynamics, revealing highly correlated, non-Markovian processes and large fluctuations in different tunneling regimes.

Contribution

It provides detailed experimental insights into charge transport regimes and fluctuations in silicon quantum dots, highlighting correlations and non-Markovian effects.

Findings

Large current fluctuations in inelastic cotunneling regime

Unusually large fluctuations at low energy in elastic cotunneling

Correlation between transport regimes and internal quantum dot states

Abstract

Quantum shot noise probes the dynamics of charge transfers through a quantum conductor, reflecting whether quasiparticles flow across the conductor in a steady stream, or in syncopated bursts. We have performed high-sensitivity shot noise measurements in a quantum dot obtained in a silicon metal-oxide-semiconductor field-effect transistor. The quality of our device allows us to precisely associate the different transport regimes and their statistics with the internal state of the quantum dot. In particular, we report on large current fluctuations in the inelastic cotunneling regime, corresponding to different highly-correlated, non-Markovian charge transfer processes. We have also observed unusually large current fluctuations at low energy in the elastic cotunneling regime, the origin of which remains to be fully investigated.