**5. Conclusions**

In this chapter, we have summarized the potential applications of NV defect in diamond, including sensors for the detection of temperature, electric and magnetic fields as well as quantum communication and computing. Furthermore, the growth methods of diamond are introduced, such as HPHT and CVD methods. For the creation of NV defects in diamond, NV centers can be generated during the grow of diamond by adding nitrogen gas source in the mixed gas source. Additionally, NV defects can also be obtained after diamond growth, notably ion implantation, femtosecond laser irradiation, and electron beam irradiation methods.
