Spontaneous emission of phonons by coupled quantum dots

TL;DR

This paper uncovers a quantum interference effect in coupled semiconductor quantum dots where spontaneously emitted phonons interfere, significantly influencing nonlinear transport properties even at near-zero temperatures.

Contribution

It introduces the concept of phonon interference in coupled quantum dots and relates it to subradiance phenomena, explaining observed oscillations in current-voltage characteristics.

Findings

Interference effect dominates nonlinear transport at low temperatures.

Spontaneous phonon emission exhibits a double-slit-like interference pattern.

Explains oscillations in current-voltage characteristics of coupled dots.

Abstract

We find an interference effect for electron-phonon interactions in coupled semiconductor quantum dots that can dominate the nonlinear transport properties even for temperatures close to zero. The intradot electron tunnel process leads to a `shake up' of the phonon system and is dominated by a double-slit-like interference effect of spontaneously emitted phonons. The effect is closely related to subradiance of photons (Dicke effect) in a laser-trapped two-ion system and explains the oscillations in the nonlinear current-voltage characteristics of coupled dots observed recently.