Suppression of Decoherence tied to Electron-Phonon Coupling in Telecom-Compatible Quantum Dots: Low-threshold Reappearance Regime for Quantum State Inversion

TL;DR

This paper demonstrates that by engineering quantum dot size, shape, and symmetry, it is possible to significantly suppress electron-phonon decoherence, enabling efficient quantum state control at telecom wavelengths for quantum networks.

Contribution

The study shows how tailoring quantum dot properties reduces decoherence, achieving low-threshold quantum state inversion compatible with telecom infrastructure.

Findings

Four-fold reduction in excitation threshold for quantum state inversion.

Good agreement between experimental results and theoretical models.

Quantum dot symmetry offers an additional control parameter for electron-phonon interactions.

Abstract

We demonstrate full suppression of dephasing tied to deformation potential coupling of confined electrons to longitunidal acoustic (LA) phonons in optical control experiments on large semiconductor quantum dots (QDs) with emission compatible with the low-dispersion telecommunications band at 1.3~$\mu$m. By exploiting the sensitivity of the electron-phonon spectral density to the size and shape of the QD, we demonstrate a four-fold reduction in the threshold pulse area required to enter the decoupled regime for exciton inversion using adiabatic rapid passage (ARP). Our calculations of the quantum state dynamics provide good agreement with our experimental results and indicate that the symmetry of the QD wave function provides an additional means to engineer the electron-phonon interaction. Our findings will support the development of solid-state quantum emitters in future distributed quantum networks using semiconductor QDs.