Nuclear tunneling and dynamical Jahn-Teller effect in graphene with vacancy

We show that the substitutional vacancy in graphene forms a dynamical Jahn-Teller center. The adiabatic potential surface resulting from the electron-lattice coupling was computed using density-functional methods, and subsequently the Schrödinger equation was solved for the nuclear motion. Our calculations show a large tunneling splitting 3Γ estimated to be about 65 cm -1. The effect results in a large delocalization of the carbon nuclear wave functions around the vacancy, leading to a significant broadening of the Jahn-Teller active sp2σ electron states. The tunneling splitting should be observable in electron paramagnetic resonance and two-photon resonance scattering experiments. © 2012 American Physical Society.