Stanwix, Paul L.Pham, LinhMaze, Jeronimo R.Le Sage, DavidYeung, Tsun KwanCappellaro, PaolaHemmer, Philip R.Yacoby, AmirLukin, MikhailWalsworth, Ronald2012-07-032010Stanwix, Paul L., Linh M. Pham, Jeronimo R. Maze, David Le Sage, Tsun K. Yeung, Paola Cappellaro, Philip R. Hemmer, Amir Yacoby, Mikhail D. Lukin and Ronald L. Walsworth. 2010. Coherence of nitrogen-vacancy electronic spin ensembles in diamond. Physical Review B 82(20): 201201.1098-01211550-235Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:8951177We present an experimental and theoretical study of electronic spin decoherence in ensembles of nitrogen-vacancy (NV) color centers in bulk high-purity diamond at room temperature. Under appropriate conditions, we find ensemble NV spin coherence times (\(T_2\)) comparable to that of single NV with \(T_2>600 \mu s\) for a sample with natural abundance of \(^{13}\)C and paramagnetic impurity density ∼1015 cm\(^{−3}\). We also observe a sharp decrease in the coherence time with misalignment of the static magnetic field relative to the NV electronic spin axis, consistent with theoretical modeling of NV coupling to a \(^{13}\)C nuclear-spin bath. The long coherence times and increased signal-to-noise provided by room-temperature NV ensembles will aid many applications of NV centers in precision magnetometry and quantum information.en-USsingle spinsdynamicsqubitsstateJournal Article2012-07-0310.1103/PhysRevB.82.201201