Nanoscale zero-field electron spin resonance spectroscopy

Fei Kong,Pei Yu,Jihu Su,Jiangfeng Du,Zhecheng Wang,Fazhan Shi,Pengju Zhao,Xiangyu Ye,Zhuoyang Qin

doi:10.1038/s41467-018-03969-4

Abstract

Electron spin resonance (ESR) spectroscopy has broad applications in physics, chemistry, and biology. As a complementary tool, zero-field ESR (ZF-ESR) spectroscopy has been proposed for decades and shown its own benefits for investigating the electron fine and hyperfine interaction. However, the ZF-ESR method has been rarely used due to the low sensitivity and the requirement of much larger samples than conventional ESR. In this work, we present a method for deploying ZF-ESR spectroscopy at the nanoscale by using a highly sensitive quantum sensor, the nitrogen vacancy center in diamond. We also measure the nanoscale ZF-ESR spectrum of a few P1 centers in diamond, and show that the hyperfine coupling constant can be directly extracted from the spectrum. This method opens the door to practical applications of ZF-ESR spectroscopy, such as investigation of the structure and polarity information in spin-modified organic and biological systems.

Highlights

Electron spin resonance (ESR) spectroscopy has broad applications in physics, chemistry, and biology
Combining with site-directed spinlabeling of radicals, ESR has been widely used to study basic molecular mechanisms in biological systems[1], such as structure[2], dynamics[3], and polarity[4]. This information is derived from the electron fine and hyperfine interaction, which can be obtained from the ESR spectra with accuracy limited by the inhomogeneous line broadening
The zero-field ESR (ZF-ESR) spectroscopy provides a straightforward method for investigating the intrinsic interactions, it has rare applications due to the much lower sensitivity compared with the conventional ESR (ESR refers to non-zero field ESR)

Summary

Introduction

Electron spin resonance (ESR) spectroscopy has broad applications in physics, chemistry, and biology. NV center-based ESR has been demonstrated using both double electron–electron resonance (DEER)[14,15,16] and cross-polarization methods[17,18], and detection of single electron spins has been realized[19,20]. We propose a different method, which does not require any manipulation of target spins, and allows for detecting nanoscale ZF-ESR signals.

Results

Conclusion