Ultrafast Laser Induces Macroscopic Symmetry-Breaking of Diamond Color Centers

We employ real-time time-dependent density functional theory (RT-TDDFT) to investigate the coupled electron-phonon-spin dynamics in negatively charged nitrogen-vacancy centers (NV$^{-}$). Laser excitation promotes minority-spin electrons within 100~fs, establishing a $C_{3v}$-symmetry breaking (3RSB) charge ordering. Subsequently, ionic motion on the potential energy surface of the excited electrons generates both symmetric oscillations of carbon-nitrogen bonds and dynamic Jahn-Teller distortions (DJT) with 3RSB. These distortions subsequently induce nonlocal coherent phonons in the diamond lattice, which propagate with 3RSB at the sound velocity ($\sim$2~\AA/fs). Meanwhile, the NV$^{-}$ spin state remains preserved during photoexcitation but undergoes rapid reorientation within 100~fs via enhanced spin-orbit-phonon coupling. Our RT-TDDFT simulations provide direct time-resolved visualization of these processes, offering novel insights into the microscopic interplay of electrons, phonons, and spins in NV$^{-}$ centers.