Researchers see almost total light extinction with tin-vacancy qubits in diamond

Researchers at the Karlsruhe Institute of Technology (KIT) and collaborating institutions have achieved almost total light extinction, 96% contrast, when coupling tin-vacancy (SnV) centers within a diamond-like microcavity. This precise control over light transmission is a key step toward realizing efficient spin-photon interfaces for quantum networks. The work demonstrates cavity-enhanced light-matter coupling in a tunable Fabry-Pérot microcavity operating at temperatures down to 1 K, maximizing Purcell enhancement and delivering a 4.1(1) factor compared to 1.85(5) in air-like modes. The multi-institutional effort includes researchers from the University of Stuttgart, Ulm University and Fraunhofer Institute. Resonant probing of tin-vacancy centers embedded within a diamond microcavity revealed a 96% extinction contrast, nearly eliminating light transmission and demonstrating precise control over light-matter interaction. This level of light blockage is unusual for solid-state quantum systems and signifies a substantial advancement in manipulating these qubits for potential quantum technologies.…