Phonon structure in SrTiO3 under finite electric fields:: First-principles density functional approach -: art. no. 012304

A first-principles approach within the density-functional theory is proposed to determine the phonon structure of infinite solids under finite electric fields. The approach is applied to perovskite SrTiO3, confirming the existence of giant field-induced frequency shifts. Our theory further predicts a striking piezoelectric response as well as a wide-range dielectric tunability. A microscopic understanding for individual phonon modes under finite electric fields is also provided.