CNI 532nm laser used in Nitrogen-vacancy Center Detection.Electron spin resonance (ESR) spectroscopy has broad applications in physics, chemistry, and biology. However, the traditional zero-fifield ESR (ZF-ESR) method has been rarely used due to the low sensitivity and the requirement of much larger samples than conventional ESR.

The University of Science and Technology of China presents a method for deploying ZF-ESR spectroscopy at the nanoscale by using a highly sensitive quantum sensor, the nitrogen vacancy center in diamond. This method opens the door to practical applications of ZF-ESR spectroscopy, such as investigation of the structure and polarity information in spin-modifified organic and biological systems. They use a CNI 532nm laser and their paper is published in Nature Communications.