@misc{oai:repo.qst.go.jp:00078265,
 author = {増山, 雄太 and IWASAKI, Takayuki and 波多野, 睦子 and 大島, 武 and Masuyama, Yuta and Hatano, Mutsuko and Ohshima, Takeshi},
 month = {Dec},
 note = {Nitrogen-vacancy (NV) color centers in diamond are promising solid-state quantum sensors working at room temperature. The number of NV centers limits the magnetic sensitivity of the quantum magnetometer. Increasing the number of NV centers is a challenging task due to technical issues such as microwave power density, detection noise.
Here, we developed the sensor system with a large detection volume which contains a lot of NV centers. The microwave circuit enhances microwave power density. Digital filter with frequency modulation of microwave allows us to detect the magnetic field with low noise. 
Consequently, we obtained a DC magnetic field sensitivity of 980 pT/√Hz.
This work was supported by MEXT Quantum Leap Flagship Program (MEXT Q-LEAP) Grant Number JPMXS0118067395., 第3回QST国際シンポジウムへの参加},
 title = {Highly sensitive diamond quantum sensor with large sensor volume toward magnetoencephalography},
 year = {2019}
}