Photonic "hourglass" design beyond the standard bulk model of phonon decoherence

TL;DR

This paper investigates how vibrational modes affect the photonic hourglass structure's ability to emit high-quality single photons, revealing that high-Q cavities can mitigate phonon decoherence even in quasi-1D geometries.

Contribution

It provides a detailed analysis of vibrational effects in the photonic hourglass, demonstrating robustness against phonon decoherence due to Purcell enhancement.

Findings

Robust single-photon indistinguishability achieved despite vibrational modes.

High-Q cavities significantly reduce phonon decoherence effects.

Vibrational impact in quasi-1D differs from bulk assumptions.

Abstract

We study the impact of mechanical vibrations on the performance of the photonic "hourglass" structure, which is predicted to emit single photons on-demand with near-unity efficiency and indistinguishability. Previous investigations neglected the impact of vibrational modes inherent to this quasi-1D geometry, relying instead on a three-dimensional bulk assumption for the phonon modes. However, it has been shown that phonon decoherence has a much stronger impact in 1D structures as compared with bulk media. Here, we surprisingly demonstrate the robustness of the photonic hourglass design, achieving close-to-unity indistinguishability even by incorporating a detailed description of the vibrational modes. We explain this unexpected result in terms of the large Purcell enhancement of the hourglass single-photon source, which eliminates the negative effect of phonons. Our findings highlight the key role of high-Q optical cavities in mitigating the detrimental effect of phonon decoherence, even for structures of reduced dimensionality.