@article{7eeaff1d073247f68f7cfd94ddcdd002,
title = "Fiber-Coupled Diamond Micro-Waveguides toward an Efficient Quantum Interface for Spin Defect Centers",
abstract = "We report the direct integration and efficient coupling of nitrogen vacancy (NV) color centers in diamond nanophotonic structures into a fiber-based photonic architecture at cryogenic temperatures. NV centers are embedded in diamond micro-waveguides (μWGs), which are coupled to fiber tapers. Fiber tapers have low-loss connection to single-mode optical fibers and hence enable efficient integration of NV centers into optical fiber networks. We numerically optimize the parameters of the μWG-fiber-taper devices designed particularly for use in cryogenic experiments, resulting in 35.6% coupling efficiency, and experimentally demonstrate cooling of these devices to the liquid helium temperature of 4.2 K without loss of the fiber transmission. We observe sharp zero-phonon lines in the fluorescence of NV centers through the pigtailed fibers at 100 K. The optimized devices with high photon coupling efficiency and the demonstration of cooling to cryogenic temperatures are an important step to realize fiber-based quantum nanophotonic interfaces using diamond spin defect centers.",
author = "Masazumi Fujiwara and Oliver Neitzke and Tim Schr{\"o}der and Schell, {Andreas W.} and Janik Wolters and Jiabao Zheng and Sara Mouradian and Mohamed Almoktar and Shigeki Takeuchi and Dirk Englund and Oliver Benson",
note = "Funding Information: The authors thank Dr. G{\"u}nter Kews for the technical support of the room-temperature optical experiments. This research was supported in part by Bilateral Joint Research Project by JSPS and DAAD, Deutsche Forschungsgemeinschaft (DFG, FOR1493), European Union (EFRE, project iMiLQ), Japan Society for the Promotion of Science (JSPS, KAKENHI 26220712, 23244079, 26706007, 26610077, 16K13646, 17H02741), Japan Science and Technology Agency (JST, CREST program), MEXT-LEADER program and the U.S. Army Research Laboratory Center for Distributed Quantum Information (CDQI). M.F. acknowledges financial support by Yamada Science Foundation. S.M. was supported in part by the U.S. National Science Foundation IQuISE program and the NSF program ACQUIRE: “Scalable Quantum Communications with Error-Corrected Semiconductor Qubits”. M.F. and T.S. are recipients of a fellowship from Alexander von Humboldt Foundation. A.W.S. and M.A. thank JSPS for the fellowship for overseas researchers. Funding Information: †Institut f{\"u}r Physik, Humboldt Universitaẗ zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany ‡Department of Chemistry, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan §Research Institute for Electronic Science, Hokkaido University, N20W10, Kita-Ward, Sapporo 001-0020, Hokkaido, Japan ∥The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan ⊥Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States #Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen, Denmark ∇Physics Department, Assiut University, Assiut 71516, Egypt ○Department of Electronic Science and Engineering, Kyoto University, Kyoto Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan Publisher Copyright: {\textcopyright} 2017 American Chemical Society.",
year = "2017",
month = oct,
day = "31",
doi = "10.1021/acsomega.7b01223",
language = "English",
volume = "2",
pages = "7194--7202",
journal = "ACS Omega",
issn = "2470-1343",
publisher = "American Chemical Society",
number = "10",
}