Design and low-temperature characterization of a tunable microcavity for diamond-based quantum networks

TL;DR

This paper presents the design, fabrication, and low-temperature characterization of a tunable microcavity for diamond-based quantum networks, aiming to enhance NV center emission and entanglement.

Contribution

It introduces a novel cryogenic microcavity with high finesse and spectral tuning capabilities for improved quantum network performance.

Findings

Cavity finesse achieved between 4,000 and 12,000 at cryogenic temperatures

Sub-nanometer cavity stability demonstrated

Modeling indicates potential three orders of magnitude increase in entanglement success

Abstract

We report on the fabrication and characterization of a Fabry-Perot microcavity enclosing a thin diamond membrane at cryogenic temperatures. The cavity is designed to enhance resonant emission of single nitrogen-vacancy centers by allowing spectral and spatial tuning while preserving the optical properties observed in bulk diamond. We demonstrate cavity finesse at cryogenic temperatures within the range of F = 4,000-12,000 and find a sub-nanometer cavity stability. Modeling shows that coupling nitrogen-vacancy centers to these cavities could lead to an increase of remote entanglement success rates by three orders of magnitude.