Slot-waveguide cavities for optical quantum information applications

TL;DR

This paper demonstrates that slot-waveguide cavities, especially in diamond and GaP, can achieve ultra-small modal volumes and high Rabi frequencies, advancing solid-state quantum optical devices.

Contribution

It introduces the use of slot-waveguide geometries for quantum optical cavities compatible with diamond color centers, achieving significantly smaller modal volumes and higher coupling strengths.

Findings

Achieved ultra-small cavity modal volumes in diamond and GaP SWCs.

Demonstrated increased single-photon Rabi frequencies (~10^11 Hz).

Compared performance favorably to previous diamond photonic crystal cavities.

Abstract

To take existing quantum optical experiments and devices into more practical regimes requires the construction of robust, solid-state implementations. In particular, to observe the strong-coupling regime of atom-photon interactions requires very small cavities and large quality factors. Here we show that the slot-waveguide geometry recently introduced for photonic applications is also promising for quantum optical applications in the visible regime. We study diamond- and GaP-based slot-waveguide cavities (SWCs) compatible with diamond colour centres e.g. nitrogen-vacancy (NV) defect, and show that one can achieve increased single-photon Rabi frequencies of order O(10^11) Hz in ultra-small cavity modal volumes, nearly 2 orders of magnitude smaller than previously studied diamond-based photonic crystal cavities.