@misc{oai:repo.qst.go.jp:00078278,
 author = {Onoda, Shinobu and Higuchi, Taisei and Saiki, Seiichi and Saito, Hiroyuki and Nishihara, Yu and Kada, Wataru and Hanaizumi, Osamu and Ohshima, Takeshi and Onoda, Shinobu and Higuchi, Taisei and Saiki, Seiichi and Saito, Hiroyuki and Ohshima, Takeshi},
 month = {Dec},
 note = {Nitrogen vacancy (NV) center is composed of a substitutional nitrogen and a vacancy on adjacent lattice sites in diamond. An electron spin of NV center can be detected and manipulated at room temperature, and spin state are utilized for quantum sensors for measuring small physical quantities. In order to improve the sensitivity of quantum sensors, it is important to create an NV center at a high concentration with controlled orientation. An electron beam which enables to introduce vacancies in nitrogen rich diamond substrate is useful to create dense NV centers. The highest NV concentration of 45 ppm has been achieved by combination of the electron beam irradiation with high temperature annealing in vacuum condition. However, orientation of NV centers created by the electron beam is always random. On the other hand, chemical vapor deposition (CVD) technique has realized the orientation of NV centers. A disadvantage of CVD technique is less NV center concentration compared with electron beam technique. In 2014, ab initio theoretical calculation showed that the orientation of NV centers can be controlled by high temperature annealing in the presence of strain. In this study, the anisotropic high-pressure-high-temperature (HPHT) treatment was applied to introduce the strain during high temperature annealing., The 2nd International Forum on Quantum Metrology and Sensing (IFQMS)},
 title = {Nitrogen Vacancy Center Created by Anisotropic and Hydrostatic High-Pressure-High-Temperature Treatment after Electron Irradiation},
 year = {2019}
}