New Color Centers in Diamond for Quantum Applications

Color centers in diamond are promising platforms for quantum communication and quantum sensing applications. All the defects in diamond reported so far emit photons in the visible to near-infrared region, which experience high losses in fiber optics and scattering media such as biological samples. Furthermore, no color centers observed thus far exhibit coherence times comparable to nitrogen vacancies at elevated temperatures. Here, we report the experimental observation of two new color centers in diamond that emit in the telecom band. The first color center emits in the telecom O-band [1]. From absorption, photoluminescence, and transient absorption spectroscopy, we identify a zero-phonon line at 1221 nm with phonon replicas separated by 42 meV and an excited state lifetime of ~270 ps. The second is substitutional Er³⁺ incorporated in diamond, which emits in the telecom C-band. Finally, we deploy our spectroscopy and materials characterization pipeline to investigate other new defects in diamond as potential candidates for quantum sensing by characterizing spin dynamics using pulsed electron spin resonance.



[1] S. Mukherjee et al., Nano Lett. 2023, 23, 7, 2557–2562.