High Q-Factor Diamond Optomechanical Resonators with Silicon Vacancy Centers at Millikelvin Temperatures

The authors would like to thank M. Bhaskar, D. Assumpcao, and C. Knaut for the useful discussions. G.J. was supported in part by the Natural Sciences and Research Council of Canada (NSERC). C.C. was supported in part by Singapore’s Agency for Science, Technology and Research (A*STAR). B.P. acknowledges financial support through a Horizon 2020 Marie Skłodowska-Curie Actions global fellowship (COHESiV, Project No. 840968) from the European Commission and through Q-NEXT, supported by the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers. K.K. acknowledges financial support from JSPS Overseas Research Fellowships (Project No. 202160592). S.M. acknowledges support from the IQIM Postdoctoral Fellowship. Research funding: NSF Engineering Research Center for Quantum Networks (EEC-1941583), NSF Science and Technology Center for Integrated Quantum Materials (NSF DMR-1231319), AFOSR (FA9550-20-1-01015 and FA9550-23-1-0333), ARO (W911NF1810432), ONR (N00014-20-1-2425), and Harvard Quantum Initiative (HQI). This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network (NNIN), which is supported by the National Science Foundation award ECS-0335765. CNS is part of Harvard University.