Self-Aligned Quasi-1D Chains of NV Centers Formed by Swift Heavy Ions Irradiation for Quantum Information Processing

High energy (~1 GeV), heavy ion (e. g. gold) irradiation of single crystal diamonds leads to the conversion of native nitrogen atoms to nitrogen-vacancy centers (NV) along the ion trajectories. The resulting self-aligned quasi-1D chains of coupled NV centers with lengths in the tens of micron range can be building blocks for quantum information processing and they provide insights into harsh radiation-matter interactions [1, 2].
Here, we report on the study of individual quasi-1D chains of NV centers created by using 1 GeV Au ions with a low fluence of 10⁸ ions/cm². By using 3D-resolved confocal photoluminescence (PL), we visualized individual 1D NV chains appearing as isolated bright luminescence strings, which indicates the presence of densely coupled NV centers created along a single ion trajectories. The up to 30 µm length of 1D chains of NV centers is consistent with Monte Carlo simulations of the range of high energy, heavy ions. Molecular dynamics simulations further indicate that both isolated vacancies and defect clusters form along ion trajectory through electronic stopping processes. We further quantify the electron spin properties of 1D NV chains through optical detection of magnetic resonance (ODMR). Importantly, individual 1D NV chains show enhanced electron spin resonance contrast and coherence time compared to a background of NV centers that are present in the nitrogen doped diamonds. Our findings suggest the possibility that NV centers in 1D chains with dipolar interaction between NV centers can improve sensitivity in NV-based magnetometry applications and provide guidance on the engineering of 1D chains of NV centers with minimal disorder for applications in quantum information processing.

Acknowledgments:
Work at Berkeley Lab was supported by the Office of Science, Office of Fusion Energy Sciences, and by the Molecular Foundry, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
References:
[1] R. E. Lake, et al., “Direct formation of nitrogen-vacancy centers in nitrogen doped diamond along the trajectories of swift heavy ions”, Appl. Phys. Lett. 118, 084002 (2021) doi: 10.1063/5.0036643
[2] W. Liu et al., “Optical and spin properties of nitrogen vacancy centers formed along the tracks of high energy heavy ions”, arXiv:2403.03570