SrTiO3 (STO) is a tetragonal ferroelectric material below 105K. At room temperature, it is paraelectric with a centrosymmetric perovskite structure. At sufficiently low temperatures (below 36 K) ferroelectric ordering is suppressed by quantum fluctuations which makes STO an example of the quantum paraelectric system. Recently it has been shown that an intense THz electric field can coherently drive ferroelectric soft modes that overcome quantum fluctuations and induce quantum paraelectric - to- ferroelectric phase transition. In this talk, we will discuss the origin of the soft phonon modes in STO, the principles of THz spectroscopy, and the importance of electronic degrees of freedom for low-frequency modes.
Note: this event will be hybrid. The live talk occuring in Loomis 276 will be simultaneously broadcast via Zoom. The Zoom link will be sent to the Graduate Student and PDRA mailing lists. If you are not on one of those lists and are interested in attending, please email Cat Kengle at ckengle2@illinois.edu for the link.