Giant shift upon strain on the fluorescence spectrum of VN NB color centers in *h*-BN

We study the effect of strain on the physical properties of the nitrogen antisite-vacancy pair in hexagonal boron nitride (h-BN), a color center that may be employed as a quantum bit in a two-dimensional material. With group theory and ab initio analysis we show that strong electron-phonon coupling plays a key role in the optical activation of this color center. We find a giant shift on the zero-phonon-line (ZPL) emission of the nitrogen antisite-vacancy pair defect upon applying strain that is typical of h-BN samples. Our results provide a plausible explanation for the experimental observation of quantum emitters with similar optical properties but widely scattered ZPL wavelengths and the experimentally observed dependence of the ZPL on the strain.

Song Li, Jyh-Pin Chou, Alice Hu, Martin B. Plenio, Péter Udvarhelyi, Gergő Thiering, Mehdi Abdi, Adam Gali