Low Temperature Symmetric Dynamical Decoupling in NV Centers

Increasing the coherence time of an arbitrary spin state is a major step toward enhanced quantum information and quantum sensing in variety of quantum systems. In this work, we explore several dynamical decoupling techniques in order to determine a robust protocol for increasing the coherence time of an ensemble of nitrogen-vacancy (NV) centers. By optimizing experimental parameters and using a concatenated version of the XY8 dynamical decoupling sequence, we preserve a general spin state up to almost 30 ms at a temperature of 77 K. The concatenated sequence performs better than standard CPMG and XY sequences on an arbitrary spin state and thus may be immediately applied to enhance the sensitivity of nv-based magnetometers. Additional potential applications include quantum memory and interaction-dominated dynamics.