Author(s)

Zihan Li, Shaohui Meng, Senhao Zhao, Shuo Lin, Jianqiang Lu, Zihao Wang

Corresponding Author

Zihan Li

Abstract

The development of modern quantum technologies, such as quantum computing and quantum communication, relies on the use of qubits, a novel computational method distinct from classical bits. The nitrogen-vacancy (NV) center, with its excellent optical properties and strong coherence, has been highly praised by both the physics and engineering communities as an outstanding qubit. It is widely applied in experiments such as quantum key distribution and biological fluorescence labeling. The spin of the NV center can be manipulated and detected using lasers and microwaves. Additionally, due to its electron spin coherence time reaching the millisecond level, the NV center is considered a highly promising system for quantum computing. Experiments utilizing NV quantum registers and quantum error correction have been demonstrated. Moreover, NV centers can also serve as nanoscale sensors for measuring physical quantities such as magnetic fields, electric fields, and temperature. Internationally, NV centers have been used to detect nuclear magnetic resonance signals in organic materials and to measure temperature within biological cells. Another technology with comparable impact to the NV center is Optically Detected Magnetic Resonance (ODMR), which generates spectral lines through the double resonance phenomenon between the intrinsic vibrations of molecules or atoms and externally applied microwaves. Obtaining high-quality spectral lines, i.e., those closely matching the ideal model, is of crucial importance for both scientific research and industrial production. In this paper, we first introduce the physical basis of the NV center, including its physical structure, energy level structure, and the eight-peak curve of optically detected magnetic resonance. We then analyze the line shape of the ODMR spectrum and demonstrate that it follows a Lorentzian profile. Finally, we prove the effect of magnetic field gradient on the spectral line width (full width at half maximum, FWHM).

Keywords

nitrogen-vacancy (nv) centers, optically detected magnetic resonance (odmr), quantum computing, magnetic field gradient, spectral line width, lorentzian profile