Single-spin resonance in van der Waals embedded paramagnetic defect

Nathan Chejanovsky^1,2, Amlan Mukherjee¹, Jianpei Geng¹, Yu-Chen Chen^1,9*, Youngwook Kim^2,3, Andrej Denisenko¹, Amit Finkler⁴, Takashi Taniguchi⁵, Kenji Watanabe⁶, Durga Bhaktavatsala Rao Dasari¹, Philipp Auburger⁷, Adam Gali^7,8, Jurgen H. Smet², Jörg Wrachtrup^1,2

¹3. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany
²Max Planck Institute for Solid State Research, Stuttgart, Germany
³Department of Emerging Materials Science, DGIST, Daegu, Korea
⁴Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
⁵International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
⁶Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
⁷Wigner Research Centre for Physics, Budapest, Hungary
⁸Department of Atomic Physics, Budapest University of Technology and Economics, Budapest, Hungary
⁹Current address: Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan

* Presenter:Yu-Chen Chen, email:Larrychen1987@hotmail.com

Solid-state defects with optically addressable spin states are a promising platform for the achievements of many quantum applications, such as quantum photonics devices and scalable quantum information architectures etc [1,2]. A plethora of single-photon emitters have been identified in the atomic layers of two-dimensional van der Waals materials [3,4,5]. Amongst them, some quantum emitters in hexagonal boron nitride (hBN) were found to exhibit magnetic field-dependent optical emission such as ensemble of boron vacancy defects [6].
Here, we report on a set of isolated optical emitters embedded in hexagonal boron nitride that exhibit optically detected magnetic resonance. We also demonstrated that one of them is single spin defect. The defect spins show an isotropic g_e-factor of ~2 and zero-field splitting below 10 MHz. The photokinetics of one type of the defects is compatible with ground-state electron-spin paramagnetism. We extracted spin-lattice relaxation times T₁ of 13-17 μs with estimated spin coherence times T₂* of around 40-60 ns. We also investigated into the spin dynamics and provided a simple model of the electronic structure. We also used the density functional theory to investigate some potential defect complex candidates. Our results provide some insight into the chemical structure of the defects.
Reference
1.Bodey, J. H. et al. npj Quantum Information 5, 95 (2019).
2.Awschalom, D. D. et al. Nat. Photonics 12, 5160527 (2018).
3.Srivastava, A. et al. Nat. Nanotechnol. 10, 491-496 (2015).
4.Cassabois, G., Valvin, P. & Gil, B. Nat. Photonics 10, 262-266 (2016).
5.Tran, T. T., Bray, K., Ford, M. J., Toth, M. & Aharonovich, I. Nat. Nanotechnol. 11, 37-41 (2015).
6.Gottscholl, A. et al. Nat. Mater. 19, 540–545 (2020).

Keywords: Quantum control, Single photons, Two-dimensional materials, Atomic and nanoscale characterization