Phonon-assisted resonant tunneling through a triple-quantum-dot: a phonon-signal detector

TL;DR

This paper investigates how electron-phonon interactions influence current and shot noise in a triple-quantum-dot system, revealing phonon-assisted resonant tunneling peaks that enable phonon detection or generation.

Contribution

It introduces a nonperturbative approach to analyze phonon effects in triple-quantum-dot tunneling, highlighting phonon-assisted resonant phenomena and potential applications as a phonon detector.

Findings

Enhanced current spectrum due to phonon effects

Identification of phonon-absorption and emission resonant peaks

Potential use as a sensitive phonon-signal detector

Abstract

We study the effect of electron-phonon interaction on current and zero-frequency shot noise in resonant tunneling through a series triple-quantum-dot coupling to a local phonon mode by means of a nonperturbative mapping technique along with the Green function formulation. By fixing the energy difference between the first two quantum dots to be equal to phonon frequency and sweeping the level of the third quantum dot, we find a largely enhanced current spectrum due to phonon effect, and in particular we predict current peaks corresponding to phonon-absorption and -emission assisted resonant tunneling processes, which shows that this system can be acted as a sensitive phonon-signal detector or as a cascade phonon generator.