One-Step Site-Specific Creation of Quantum Emitters in Hexagonal Boron Nitride

Quantum emitter is one of the crucial components for realizing various quantum information technologies, including quantum communication and quantum computing. In particular, quantum emitters in solid-state materials provide significant benefits such as structural stability and possibility of large-scale operation integrated into on-chip integrated photonic circuits. Recently, hexagonal Boron Nitride (hBN), a wide-bandgap two-dimensional material, has attracted significant interest as a host for quantum emitters operating at room temperature [1]. However, the deterministic creation of quantum emitters in hBN often requires multiple steps followed by high-temperature annealing [2,3]. In this work, we introduce a one-step method for creating quantum emitter arrays through site-specific local stress application [4].

A nanoindentation machine with a nanoscale diamond tip precisely applies mechanical stress to exfoliated hBN flakes. This simple approach creates quantum emitters at the indented site without additional pre-patterning or post-annealing processes. The yield of successful indentations and quantum emitters both depends on the tip loading speed, maximum forces, and the thickness of the hBN flakes. Under optimized conditions, the generation yield of quantum emitter per indented site exceeds 80%. These quantum emitters show relatively sharp zero-phonon line emissions centered at 595 ± 18.9 nm, suggesting a similar origin for the induced defects. Our technique provides a simple and efficient route to fabricate large-scale quantum emitter arrays at room temperature.

References
[1] T. T. Tran, K. Bray, M. J. Ford, M. Toth, and I. Aharonovich, "Quantum emission from hexagonal boron nitride monolayers," Nat. Nanotechnol. 11, 37–41 (2016).
[2] T. T. Tran, C. Elbadawi, D. Totonjian, C. J. Lobo, G. Grosso, H. Moon, D. R. Englund, M. J. Ford, I. Aharanovich, and M. Toth, "Robust Multicolor Single Photon Emission from Point Defects in Hexagonal Boron Nitride", ACS Nano 10, 7331–7338 (2016).
[3] X. Xu, Z. O. Martin, D. Sychev, A. S. Lagutchev, Y. P. Chen, T. Taniguchi, K. Watanabe, V. M. Shalaev, and A. Boltasseva, "Creating Quantum Emitters in Hexagonal Boron Nitride Deterministically on Chip-Compatible Substrates", Nano Lett. 21, 8182–8189 (2021).
[4] S. Karankova, Y. Lee, C. Jang, Y.-W. Song, and H. Moon, "One-Step Creation of Quantum Emitter Arrays in Hexagonal Boron Nitride by Local Stress Application", Adv. Optical Mater. 2403018 (2024).