Design principles for >90% efficiency and >99% indistinguishability broadband quantum dot cavities

TL;DR

This paper presents design principles for broadband quantum dot cavities achieving over 90% efficiency and over 99% photon indistinguishability, crucial for quantum computing applications.

Contribution

It introduces a detailed analysis of micropillar cavity design, optimizing structural parameters to enhance efficiency and indistinguishability beyond previous estimates.

Findings

Achieved internal efficiency of 90.5%-96.4%.

Demonstrated reduction of phonon sideband by a factor of 5-33.

Predicted photon indistinguishability of 99.2%-99.8%.

Abstract

Quantum dots have the potential to be the brightest deterministic single photon source with plausible high end applications in quantum computing and cluster state generation. In this work, we re-examine the design of simple micropillars by meticulously examining the structural effects of the decay into leaky channels beyond the atom-like cavity estimation. We show that precise control of the side losses with the diameter and avoidance of propagating Bloch modes in the DBR structure can result in easy to manufacture broadband (Q$\approx750-2500$) micropillars and demonstrate extremely high internal efficiency ($90.5\%-96.4\%$). We also demonstrate that such cavities naturally decouple from the phonon sideband, with the phonon sideband reducing by a factor of $5-33$ allowing us to predict that the photons should show $99.2\%-99.8\%$ indistinguishability.