Magnetic resonance (MR), such as nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR), can probe the local structure and dynamic properties of various systems, making them among the most powerful and versatile analytical methods. However, their intrinsically low sensitivity precludes MR analyses of samples with very small volumes; e.g., more than 1010 electron spins are typically required to observe EPR signals at room temperature. A vast improvement in the current limits of MR will enable the imaging of structures and conformational changes of molecules in solution at the single molecule level.
A nitrogen-vacancy (NV) center in diamond is a promising candidate for applications in room temperature magnetic sensing with single spin sensitivity. In this presentation, we will discuss EPR spectroscopy using on NV centers in diamond. By employing EPR and double electron-electron resonance (DEER) techniques, we investigate impurities and coherence in diamond.1-3 We also demonstrate EPR of several electron spins using NV-based EPR spectroscopy. Moreover, we will discuss development of a high-frequency NV-based EPR system.4 This work is supported by NSF and the Searle Scholar program.
[1] F. H. Cho, ST et al., Rev. Sci. Instrum. 85, 075110 (2014).
[2] V. Stepanov and ST, arXiv:1603.07404.
[3] C. Abeywardana, ST, arXiv:1507.08744.
[4] V. Stepanov, ST et al., Appl. Phys. Lett. 106, 063111 (2015).