CMOS integrated hyperpolarized NMR using NV centers in diamond
Thanks to their unmatched specificity, nuclear magnetic resonance (NMR) and electron spin resonance (ESR) spectroscopy – jointly referred to as spin-based analytics – are tools of major importance in biology, chemistry, medicine and physics because they allow for the use of a spin (nuclear or electron) as an extremely sensitive, nanoscopic quantum probe of its electronic and magnetic environment inside a molecule. However, their main limitations are high equipment complexity and cost as well as a relatively poor sensitivity due to the very small thermal polarisation of the spin ensembles at room temperature. This poor sensitivity in turn severely compromises the required measurement time, the achievable signal-to-noise ratio and the minimum sample size. In the proposed talk, we will first introduce the so-called ESR-on-a-chip approach as a new tool in ESR spectroscopy that allows for a CMOS integrated manipulation and detection of electron spins up to very high frequencies in the hundreds of Gigahertz range. We will then discuss the use of nitrogen vacancy (NV) centers in diamond as a potential tool for hyperpolarizing a nuclear spin ensemble at ambient conditions using a laser and the abovementioned ESR-on-a-chip sensors as a compact and cheap, yet high-performance microwave source. Finally, we will introduce the NMR-on-a-chip approach, which integrates an entire NMR spectrometer into a tiny CMOS application specific integrated circuit (ASIC), as a very promising path towards miniaturizing the entire NMR spectrometer including the NV-based hyperpolarization into a compact portable system, which can extend the application range of NMR into entirely new areas including personalized medicine.