Theory of charge sensing in quantum-dot structures

TL;DR

This paper presents an exact and numerical analysis of charge sensing in quantum-dot structures, revealing characteristic conductance features influenced by temperature and capacitive coupling, aligning with recent experimental observations.

Contribution

It introduces an exactly solvable model combined with density-matrix renormalization group methods to analyze charge sensing phenomena in quantum dots.

Findings

Charge sensing causes repeated occupation cycling of current states.

Characteristic conductance features include asymmetric peaks and sawtooth/dome structures.

Temperature affects the symmetry and sharpness of these features.

Abstract

Charge sensing in quantum-dot structures is studied by an exactly solvable reduced model and numerical density-matrix renormalization group methods. Charge sensing is characterized by the repeated cycling of the occupation of current-carrying states due to the capacitive coupling to trap states which are weakly coupled to the leads. In agreement with recent experiments, it results in a variety of characteristic behaviors ranging from asymmetric Coulomb-blockade peaks to sawtooth- and dome-like structures. Temperature introduces distinct asymmetric smearing of these features and correlations in the conductance provide a fingerprint of charge-sensing behavior.