One-dimensional photonic wire as a single-photon source: Implications of cavity QED to a phonon bath of reduced dimensionality

TL;DR

This paper explores how phonon interactions in a one-dimensional nanowire environment affect the coherence of single-photon emission from quantum dots, highlighting the importance of multimode coupling for accurate predictions.

Contribution

It provides an analytical expression for 1D phonon-induced dephasing and demonstrates the necessity of multimode coupling in cavity QED models for 1D systems.

Findings

Reduced pure dephasing rate in 1D compared to bulk

Multimode coupling is essential for accurate photon indistinguishability predictions

Analytical expression for 1D phonon-induced dephasing rate

Abstract

While the semiconductor quantum dot placed in a solid-state material allows for deterministic emission of single photons, the photon indistinguishability is strongly influenced by the intrinsic coupling to lattice vibrations, phonons, of the solid-state environment. This work investigates the phonon-induced decoherence for a quantum dot placed in the one-dimensional system of a homogeneous cylindrical nanowire. Such a structure supports multiple longitudinal phonon branches, and we consider both a linear and a quadratic coupling of the emitter to these modes. Under a polaron approach, we initially derive an analytical expression for the 1D pure dephasing rate, which leads to a reduced pure dephasing rate compared with bulk. By implementing these results into a full cavity quantum electrodynamic model, we demonstrate that multimode coupling is necessary to correctly predict the indistinguishability in a 1D system, which may otherwise be significantly underestimated.