2021, Torun, Cem Güney, Schneider, Philipp-Immanuel, Hammerschmidt, Martin, Burger, Sven, Munns, Joseph H. D., Schröder, Tim

Nanostructures can be used for boosting the light outcoupling of color centers in diamond; however, the fiber coupling performance of these nanostructures is rarely investigated. Here, we use a finite element method for computing the emission from color centers in inverted nanocones and the overlap of this emission with the propagation mode in a single-mode fiber. Using different figures of merit, the inverted nanocone parameters are optimized to obtain maximal fiber coupling efficiency, free-space collection efficiency, or rate enhancement. The optimized inverted nanocone designs show promising results with 66% fiber coupling or 83% free-space coupling efficiency at the tin-vacancy center zero-phonon line wavelength of 619 nm. Moreover, when evaluated for broadband performance, the optimized designs show 55% and 76% for fiber coupling and free-space efficiencies, respectively, for collecting the full tin-vacancy emission spectrum at room temperature. An analysis of fabrication insensitivity indicates that these nanostructures are robust against imperfections. For maximum emission rate into a fiber mode, a design with a Purcell factor of 2.34 is identified. Finally, possible improvements offered by a hybrid inverted nanocone, formed by patterning into two different materials, are investigated and increase the achievable fiber coupling efficiency to 71%. © 2021 Author(s).

2021, Laucht, Arne, Hohls, Frank, Ubbelohde, Niels, Fernando Gonzalez-Zalba, M., Reilly, David J., Stobbe, Søren, Schröder, Tim, Scarlino, Pasquale, Koski, Jonne V., Dzurak, Andrew, Yang, Chih-Hwan, Yoneda, Jun, Kuemmeth, Ferdinand, Bluhm, Hendrik, Pla, Jarryd, Hill, Charles, Salfi, Joe, Oiwa, Akira, Muhonen, Juha T., Verhagen, Ewold, LaHaye, M D, Kim, Hyun Ho, Tsen, Adam W, Culcer, Dimitrie, Geresdi, Attila, Mol, Jan A., Mohan, Varun, Jain, Prashant K., Baugh, Jonathan

Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon.