Section 3 Applications

**Chapter 4**

**Abstract**

optics.

**1. Introduction**

the atomic level.

**49**

NV Centers

magnetometry, wide field-of-view optics

Atomic Scale Magnetic Sensing

and Imaging Based on Diamond

The development of magnetic sensors simultaneously satisfying high magnetic sensitivity and high spatial resolution becomes more important in a wide range of fields including solid-state physics and life science. The nitrogen-vacancy (NV) center in diamond is a promising candidate to realize nanometer-scale magnetome-

atomic-scale size and versatile operation condition. Recent experiments successfully demonstrate the use of NV center in various sensing and imaging applications. In this chapter, we review the basic sensing mechanisms of the NV center and introduce imaging applications based on scanning magnetometry and wide field-of-view

try due to its excellent spin coherence properties, magnetic field sensitivity,

**Keywords:** magnetic sensor, diamond NV center, quantum sensing, scanning

Understanding magnetic properties at the microscopic level plays an important role in the development of modern science and technology [1, 2]. For instance, writing and reading information using nanometer size magnetic bits is the heart of massive data storage indispensable in the modern information technology [1]. Magnetic resonance imaging (MRI) which is an important medical tool of imaging the inner structures of human body is also based on sensing the magnetic response of minuscule protons with respect to radio frequency (RF) electromagnetic waves [2]. For fundamental research, on the other hand, studying magnetic phases and spin textures at the nanometer scale are one of the hottest topics in solid-state physics due to the recent discovery of exotic materials and topological phases [3–5]. Therefore, it is not too much to say that the continuous advances in modern science and technology strongly reply on the precise sensing and control of magnetism at

The paradigm of modern science and technology seems to shift from chargebased devices to spin-based systems. Nonetheless studying spins is a lot more difficult than electric charges mainly due to the lack of sensitive measurement techniques of magnetic field. For instance, the size of magnetic bits used in MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and STT-MRAM (Spin-Transfer Torque Magnetic Random-Access Memory) are less than 10

*Myeongwon Lee, Jungbae Yoon and Donghun Lee*
