2021학년도 2학기 물리학과 세미나를 안내해 드립니다.
– 연사: 박세영 교수(숭실대학교 물리학과)
– 제목: Designing materials with switchable polarizations by artificial structuring
– 초록:
In this talk, I will start with discussing the general notion of emergent symmetry breakings in condensed matter systems in which the symmetry of the ground-state wavefunction is spontaneously broken. Examples exhibiting such symmetry breakings in simple systems will be introduced. Then, I focus on a particular case, ferroelectricity, where a system exhibits broken inversion symmetry and switchable polarization. A new design principle to identity electronic ferroelectricity is presented in which combining charge-ordering and superlattice layering induce inversion symmetry breaking. As the demonstration of the proposed design principle, we use density functional theory to study the effect of artificial structuring on mixed-valence solid-solution La1/3Sr2/3FeO3 (LSFO), a system well-studied experimentally. Our calculations show that A-site (111)-layered LSFO exhibits a ferroelectric charge-ordered phase in which inversion symmetry is broken by changing the registry of the charge ordering pattern relative to the superlattice layering. Our calculations reveal that the artificial structuring of LSFO and other mixed-valence oxides with robust charge ordering in the solid solution phase can lead to charge-order-induced ferroelectricity.
– 일시: 11월 25일 오후 4시 30분
– 장소: 온라인 ZOOM(접속링크: https://ssu-ac-kr.zoom.us/j/83265012552)
많은 참여를 부탁드립니다.