High-frequency EPR of impurities on diamond

The nitrogen-vacancy (N-V) impurity center is a promising solid- state spin system for solid-state quantum information processing. Many desirable quantum properties have been found at room temperature, including long spin-coherence times, demonstration of single N-V spin quantum gate operation, discovery of rapid spin polarization and achievement of readout of single N-V spins. There have been many EPR experiments to investigate electronic structures and dynamics of impurities in diamond. Most of the studies were however performed by low- field EPR. High-frequency EPR generally has a great advantage for spectral and time resolution and absolute sensitivity due to very high spin-polarizations in high magnetic fields. High- frequency EPR for the diamond system therefore enables the investigation of ensembles of low-concentration impurities. In this presentation, we will discuss high-field properties of spin relaxations of impurities on diamond studied with 240 GHz cw and pulsed EPR.