Electron Spin Decoherence of Nitrogen-Vacancy Center Coupled to Multiple Spin Baths
Jian Xing1, Yan-Chun Chang1, Ning Wang1, Gang-Qin Liu1, Xin-Yu Pan1,2**
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 2Collaborative Innovation Center of Quantum Matter, Beijing 100871
Abstract：We present the experimental results of nitrogen-vacancy (NV) electron spin decoherence, which are linked to the coexistence of electron spin bath of nitrogen impurity (P1 center) and $^{13}$C nuclear spin bath. In previous works, only one dominant decoherence source is studied: P1 electron spin bath for type-Ib diamond; or $^{13}$C nuclear spin bath for type-IIa diamond. In general, the thermal fluctuation from both spin baths can be eliminated by the Hahn echo sequence, resulting in a long coherence time ($T_2$) of about 400 μs. However, in a high-purity type-IIa diamond where $^{13}$C nuclear spin bath is the dominant decoherence source, dramatic decreases of NV electron spin $T_2$ time caused by P1 electron spin bath are observed under certain magnetic field. We further apply the engineered Hahn echo sequence to confirm the decoherence mechanism of multiple spin baths and quantitatively estimate the contribution of P1 electron spin bath. Our results are helpful to understand the NV decoherence mechanisms, which will benefit quantum computing and quantum metrology.
2016, Vol. 33 
