Nanoscale magnetometry with NV centers in diamond
- PDF / 1,638,196 Bytes
- 7 Pages / 585 x 783 pts Page_size
- 88 Downloads / 223 Views
Introduction Advancements in magnetic detection and imaging have contributed immensely to a wide range of scientific areas from fundamental physics and chemistry to practical applications such as the data storage industry and medical science. One classic example is nuclear magnetic resonance,1,2 which has led to powerful applications such as magnetic resonance imaging3 (MRI). Over the past few decades, many advanced magnetic imaging schemes have been developed, including magnetic force microscopy,4 scanning Hall probe microscopy,5 superconducting interference devices,6 and magnetic resonance force microscopy.7 However, these techniques are often limited by operating conditions such as the need for cryogenic temperatures and/or high vacuum, hindering their use in imaging systems that require ambient conditions. Recently, negatively charged nitrogen-vacancy (NV) color centers in diamond have been proposed as a promising system for nanoscale magnetic field sensing.8–11 It has been shown, both experimentally and theoretically, that NV centers offer excellent magnetic field sensitivities.8,10 Moreover, since NV centers are atomic-sized point defects and can be localized in direct proximity to a diamond surface, they can be brought to within a few nanometers of magnetic samples, allowing for
nanometric spatial resolution. These sensing capabilities are maintained under ambient conditions (room temperature and atmospheric pressure) and can, in principle, work in a liquid environment, which is crucial for biological imaging. Over the past few years, these properties have led to rapid progress in developing NV-based magnetometers. In this review article, we cover two recently developed methods to realize NV-based magnetometers: Scanning single NV magnetometers capable of detecting a single Bohr magneton at the nanoscale, and ensemble NV wide-field imaging, enabling enhanced magnetic field sensitivities and data acquisition speeds.
Magnetic field sensing with NV centers The NV center is a point defect in diamond consisting of a substitutional nitrogen with a vacancy in its nearest neighbor lattice site (Figure 1a). The negatively charged state forms a spin triplet in the orbital ground state. The crystal field splits these spin sublevels, resulting in the ms = 0 state in the lowest energy state, and the ms = ±1 sublevels lifted by 2.87 GHz. This crystal field splitting quantizes the spin states along the N–V symmetry axis, so that in the presence of a weak external magnetic field, the ms = ±1 sublevels will have an energy splitting that is proportional to the projection of the field along the
Sungkun Hong, School of Engineering and Applied Sciences, Harvard University; [email protected] Michael S. Grinolds, Department of Physics, Harvard University; [email protected] Linh M. Pham, School of Engineering and Applied Sciences, Harvard University; [email protected] David Le Sage, Harvard-Smithsonian Center for Astrophysics; [email protected] Lan Luan, Harvard University; [email protected] Ronald L. Wals
Data Loading...
