Generation of Spin Defects by Ion Implantation in Hexagonal Boron Nitride

Abstract

Optically addressable spin defects in wide-band-gap semiconductors as promising systems for quantum information and sensing applications have recently attracted increased attention. Spin defects in two-dimensional materials are expected to show superiority in quantum sensing due to their atomic thickness. Here, we demonstrate that an ensemble of negatively charged boron vacancies (VB –) with good spin properties in hexagonal boron nitride (hBN) can be generated by ion implantation. We carry out optically detected magnetic resonance measurements at room temperature to characterize the spin properties of ensembles of VB – defects, showing a zero-field splitting frequency of ∼3.47 GHz. We compare the photoluminescence intensity and spin properties of VB – defects generated using different implantation parameters, such as fluence, energy, and ion species. With the use of the proper parameters, we can successfully create VB – defects with a high probability. Our results provide a simple and practicable method to create spin defects in hBN, which is of great significance for realizing integrated hBN-based devices.

Unveiling the Zero-Phonon Line of the Boron Vacancy Center by Cavity Enhanced Emission

“…Negatively charged boron vacancies (V − B ) in hexagonal boron nitride (hBN) are novel quantum emitters that currently attract broad interest due to their spin-dependent optical properties, even at room temperature. [1][2][3][4][5][6] The electronic states of V − B in hBN couple strongly to local vibrational modes, with a Huang-Rhys factor of ∼ 3.5. 1 Combined with singlet and triplet electronic sub-systems that are coupled via spin-orbit interaction and mix via Jahn-Teller effects, this results in a broad and largely featureless emission spectrum that complicates comparison of experimental results with first principles calculations.…”

“…1 Combined with singlet and triplet electronic sub-systems that are coupled via spin-orbit interaction and mix via Jahn-Teller effects, this results in a broad and largely featureless emission spectrum that complicates comparison of experimental results with first principles calculations. 1,7,8 Typically, the photoluminescence (PL) spectrum of ensembles of V − B exhibit a broad and featureless spectrum, peaked around 800 nm 1,5 even at liquid helium temperature. 9 Therefore, it is difficult to unambiguously identify the zero-phonon line (ZPL) of V − B from transitions involving vibrational modes of the surrounding hBN matrix.…”

Spin defects in hexagonal boron nitride for strain sensing on nanopillar arrays

“…Overall, the ODMR contrast from spin defects in hBN is still under debate. 18,24,37 An improved signal to background ratio can result in a better contrast. In addition, the strain can affect the overall transition rates within the V B − level manifold and change the rates to/from the metastable state, hence increasing the ODMR contrast.…”

Spin-active defects in hexagonal boron nitride

“…There are already many species of ions that can generate V − B defects, including H + , He + , C + , N + , Ar + , Ga + and Xe + . The implantation ion species and dose will affect the spin properties of the V − B defects, whereas the implantation energy does not affect the spin properties of the defects [205]. Especially, the FIB method allows for the patterning of arrays of spin defects due to its controllability and good positioning, although the implantation area is small.…”