Low charge-noise nitrogen-vacancy centers in diamond created using laser writing with a solid-immersion lens

• Main Authors: Yurgens, Viktoria, Zuber, Josh A, Flågan, Sigurd, De Luca, Marta, Shields, Brendan J, Zardo, Ilaria, Maletinsky, Patrick, Warburton, Richard J, Jakubczyk, Tomasz
• Format: Journal Article
• Language: English
• Published: 11-08-2021
• Subjects: Physics - Materials Science; Physics - Optics; Physics - Quantum Physics
• DOI: 10.48550/arxiv.2102.11804

ACS Photonics 2021 8(6), 1726-1734 We report on pulsed-laser induced generation of nitrogen-vacancy (NV) centers
in diamond facilitated by a solid-immersion lens (SIL). The SIL enables laser
writing at energies as low as 5.8 nJ per pulse and allows vacancies to be
formed close to a diamond surface without inducing surface graphitization. We
operate in the previously unexplored regime where lattice vacancies are created
following tunneling breakdown rather than multiphoton ionization. We present
three samples in which NV-center arrays were laser-written at distances between
~1 $\mu$m and 40 $\mu$m from a diamond surface, all presenting narrow
distributions of optical linewidths with means between 62.1 MHz and 74.5 MHz.
The linewidths include the effect of long-term spectral diffusion induced by a
532 nm repump laser for charge-state stabilization, thereby emphasizing the
particularly low charge-noise environment of the created color centers. Such
high-quality NV centers are excellent candidates for practical applications
employing two-photon quantum interference with separate NV centers. Finally, we
propose a model for disentangling power broadening from inhomogeneous
broadening in the NV center optical linewidth.