A Low-Temperature Tunable Microcavity featuring High Passive Stability and Microwave Integration

• Published in: arXiv.org 2024-12
• Main Authors: Herrmann, Yanik, Fischer, Julius, Scheijen, Stijn, Wolfs, Cornelis F J, Brevoord, Julia M, Sauerzapf, Colin, Wienhoven, Leonardo G C, Feije, Laurens J, Eschen, Martin, Ruf, Maximilian, Weaver, Matthew J, Hanson, Ronald
• Format: Article
• Language: English
• Subjects: Emitters; Frequency variation; Interface stability; Low temperature; Microcavities; Microwave photonics; Optical activity; Photons; Qubits (quantum computing); Spectral emittance; Spectral sensitivity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2409.01857

Open microcavities offer great potential for the exploration and utilization of efficient spin-photon interfaces with Purcell-enhanced quantum emitters thanks to their large spectral and spatial tunability combined with high versatility of sample integration. However, a major challenge for this platform is the sensitivity to cavity length fluctuations in the cryogenic environment, which leads to cavity resonance frequency variations and thereby a lowered averaged Purcell enhancement. This work presents a closed-cycle cryogenic fiber-based microcavity setup, which is in particular designed for a low passive vibration level, while still providing large tunability and flexibility in fiber and sample integration, and high photon collection efficiency from the cavity mode. At temperatures below 10 Kelvin, a stability level of around 25 picometer is reproducibly achieved in different setup configurations, including the extension with microwave control for manipulating the spin of cavity-coupled quantum emitters, enabling a bright photonic interface with optically active qubits.