Enhanced single-photon emission in the near infrared from a diamond color center

Individual color centers in diamond are promising for near-term quantum technologies including quantum key distribution and metrology. Here we show fabrication of an as-yet uncharacterized nickel-related complex in diamond which has photophysical properties surpassing the two main-stay centers for single-photon applications, namely, the nitrogen-vacancy and the nickel-nitrogen complex (NE8) center. This center was fabricated using focused ion-beam implantation of nickel into isolated chemical vapor-deposited diamond crystals. A possible correlation of the center to a Ni/Si complex is substantiated by a coimplantation of Ni and Si into a pure bulk diamond. Room-temperature photoluminescence studies reveal a narrow emission in the near infrared region centered at 768 nm with a lifetime as short as 2 ns