Correlative nanoscale imaging of strained hBN spin defects

Spin defects like the negatively charged boron vacancy color center ($V_B^{-}$) in hexagonal boron nitride (hBN) may enable new forms of quantum sensing with near-surface defects in layered van der Waals heterostructures. Here, we reveal the effect of strain associated with creases in hBN flakes on $V_B^{-}$ and $V_B$ color centers in hBN with correlative cathodoluminescence and photoluminescence microscopies. We observe strong localized enhancement and redshifting of the $V_B^{-}$ luminescence at creases, consistent with density functional theory calculations showing $V_B^{-}$ migration toward regions with moderate uniaxial compressive strain. The ability to manipulate these spin defects with highly localized strain offers intriguing possibilities for future 2D quantum sensors.