Dark channels in resonant tunneling transport through artificial atoms

TL;DR

This paper explores how multiple transport channels in a multilevel quantum dot affect electron tunneling, revealing conditions that can suppress current and explain negative differential conductance phenomena.

Contribution

It provides a theoretical analysis of the impact of multiple channels on tunneling behavior and identifies conditions leading to transport quenching in quantum dots.

Findings

Presence of a second transport channel can suppress tunneling current.

Distinct tunneling anisotropies influence transport behavior.

Conditions identified for negative differential conductance occurrence.

Abstract

We investigate sequential tunneling through a multilevel quantum dot confining multiple electrons, in the regime where several channels are available for transport within the bias window. By analyzing solutions to the master equations of the reduced density matrix, we give general conditions on when the presence of a second transport channel in the bias window quenches transport through the quantum dot. These conditions are in terms of distinct tunneling anisotropies which may aid in explaining the occurrence of negative differential conductance in quantum dots in the nonlinear regime.