Resonant Bonds in Symmetry-Lowering Distortion around a Si Divacancy

Abstract

We propose a novel Jahn-Teller distortion for the negatively charged divacancy ($V_{2}^{}{}_{}{}^{\ensuremath{-}}$) in Si on the basis of the first-principles total-energy calculations. This distortion is inverse to the conventional pairing Jahn-Teller distortion and the origin of its energy gain is newly discovered resonant bonds. The proposed model successfully reproduces results of electron spin resonance.