A planar defect spin sensor in a two-dimensional material susceptible to strain and electric fields
Péter Udvarhelyi, Tristan Clua-Provost, Alrik Durand, Jiahan Li, James H. Edgar, Bernard Gil, Guillaume Cassabois, V. Jacques, Ádám Gali
Abstract
Abstract The boron-vacancy spin defect ( $${\,{{\mbox{V}}}}_{{{\mbox{B}}}\,}^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mspace/> <mml:mstyle> <mml:mtext>V</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mstyle> <mml:mtext>B</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> ) in hexagonal boron nitride (hBN) has a great potential as a quantum sensor in a two-dimensional material that can directly probe various external perturbations in atomic-scale proximity to the quantum sensing layer. Here, we apply first-principles calculations to determine the coupling of the $${\,{{\mbox{V}}}}_{{{\mbox{B}}}\,}^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mspace/> <mml:mstyle> <mml:mtext>V</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mstyle> <mml:mtext>B</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> electronic spin to strain and electric fields. Our work unravels the interplay between local piezoelectric and elastic effects contributing to the final response to the electric fields. The theoretical predictions are then used to analyse optically detected magnetic resonance (ODMR) spectra recorded on hBN crystals containing different densities of $${\,{{\mbox{V}}}}_{{{\mbox{B}}}\,}^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mspace/> <mml:mstyle> <mml:mtext>V</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mstyle> <mml:mtext>B</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> centres. We prove that the orthorhombic zero-field splitting parameter results from local electric fields produced by surrounding charge defects. This work paves the way towards applications of $${\,{{\mbox{V}}}}_{{{\mbox{B}}}\,}^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mspace/> <mml:mstyle> <mml:mtext>V</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mstyle> <mml:mtext>B</mml:mtext> </mml:mstyle> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> centres for quantitative electric field imaging and quantum sensing under pressure.