Interaction effects and charge quantization in single-particle quantum dot emitters

TL;DR

This paper presents a theoretical analysis of a quantum dot single-particle emitter in quantum Hall systems, revealing how Coulomb interactions disrupt charge quantization and providing a method to calculate current pulse shapes.

Contribution

It introduces an exact mapping of the system onto the spin-boson model, showing how interactions affect charge quantization and offering a way to compute current pulses.

Findings

Coulomb interactions destroy precise charge quantization.

Charge quantization is compromised in quantum Hall edge state emitters.

A spin-boson master equation approach enables explicit current pulse calculations.

Abstract

We discuss a theoretical model of an on-demand single-particle emitter that employs a quantum dot, attached to an integer or fractional quantum Hall edge state. Via an exact mapping of the model onto the spin-boson problem we show that Coulomb interactions between the dot and the chiral quantum Hall edge state, unavoidable in this setting, lead to a destruction of precise charge quantization in the emitted wave-packet. Our findings cast doubts on the viability of this set-up as a single-particle source of quantized charge pulses. We further show how to use a spin-boson master equation approach to explicitly calculate the current pulse shape in this set-up.