Ferroelectric phase transition induced by charge transfer vibronic excitons in ferroelectric oxides

摘要

It is shown theoretically that bi-polaronic excitons (charge transfer vibronic excitons - CTVE) in ferroelectric oxides can induce a significant positive shift of the ferroelectric phase transition temperature under strong enough optical or X-ray pumping (producing CTVEs in ～ 10~(16) cm~(-3) concentration range). Incipient ferroelectrics KTaO_3 and SrTiO_3 could serve as a good example.