摘要 : The Jahn-Teller(JT)effect involves the ions M with a degenerate electronic state distorting the corner-sharing MO_(6)octahedra to lift the degeneracy,inducing strong coupling of electrons to lattice,and mediating the exotic proper... 展开 The Jahn-Teller(JT)effect involves the ions M with a degenerate electronic state distorting the corner-sharing MO_(6)octahedra to lift the degeneracy,inducing strong coupling of electrons to lattice,and mediating the exotic properties in perovskite oxides.Conversely,the anti-Jahn–Teller(AJT)effect refers to the deformation against the Jahn-Teller-distorted MO_(6)octahedra.However,it is difficult to experimentally execute both effects descending from the fine-tuning of crystal structures.We propose the AJT can be introduced by THz laser illumination at 11.71 THz in a candidate superconducting perovskite material BaBiO_(3)near room temperature.The illumination coherently drives the infrared-active phonon that excites the Raman breathing mode through the quadratic-linear nonlinear interaction.The process is characterized by the emergence of an AJT effect,accompanied by an insulator-to-metal transition occurring on the picosecond timescale.This study underlines the important role of crystal structure engineering by coherent phonon excitation in designing optoelectronic devices. 收起