Magnetic field analysis in a diamond anvil cell for Meissner effect measurement by using the diamond NV– center*

Project supported by the National Key R&D Program of China (Grant No. 2018YFA0305900) and the National Natural Science Foundation of China (Grant Nos. 11774126, 11674404, and 51772125).
Zhao Lin, Yue Donghui, Liu Cailong, Wang Min, Han Yonghao †, Gao Chunxiao
       

(a) Structure diagram of the NV− center.[14,15] (b) Electron spin resonance schematic diagram. The NV ground-state spin sublevels are separated by D = 2.87 GHz, and |ms = ±1〉 sublevels are degenerate, resulting in a single spin resonance frequency. In an external magnetic field, the degeneracy of |ms = ±1〉 sublevels will be removed, resulting in two spin resonance frequencies.[14–18]