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Physical realization of topological Roman surface by spin-induced ferroelectric polarization in cubic lattice

主 讲 人 :柴一晟     教授

活动时间:08月15日10时00分    

地      点 :理科群2号楼A408

讲座内容:

A non-orientable surface can mirror reflecting the man travelling on it. Realizing such topological object is fascinating. Here, the authors discover that antiferromagnetic-induced polarization in a solid can realize a non-orientable Roman surface.Topology, an important branch of mathematics, is an ideal theoretical tool to describe topological states and phase transitions. Many topological concepts have found their physical entities in real or reciprocal spaces identified by topological invariants, which are usually defined on orientable surfaces, such as torus and sphere. It is natural to investigate the possible physical realization of more intriguing non-orientable surfaces. Herein, we show that the set of spin-induced ferroelectric polarizations in cubic perovskite oxides AMn3Cr4O12 (A = La and Tb) reside on the topological Roman surface-a non-orientable two-dimensional manifold formed by sewing a Mobius strip edge to that of a disc. The induced polarization may travel in a loop along the non-orientable Mobius strip or orientable disc, depending on the spin evolution as controlled by an external magnetic field. Experimentally, the periodicity of polarization can be the same or twice that of the rotating magnetic field, which is consistent with the orientability of the disc and the Mobius strip, respectively. This path-dependent topological magnetoelectric effect presents a way to detect the global geometry of a surface and deepens our understanding of topology in both mathematics and physics.


主讲人介绍:

柴一晟,重庆大学物理学院教授,博士生导师。1995-2007年,本科、硕博连读于中国科学技术大学物理系;2004-2005年,丹麦Risoe国家实验室访问学者;2007-2012年,韩国国立首尔大学物理系博士后;2012-2017年,中科院物理所磁学室副研究员。2017年至今,重庆大学物理学院教授。长期从事:1、单相与复合多铁、磁电耦合行为研究;2、超导与强关联系统研究;3、热输运测量、强磁场测量及其它磁性测量方法的发展。先后在Nature Communication, Physical Review Letter,Physical Review B等期刊上以第一作者和通讯作者发表过多篇文章。目前发表文章100余篇,H因子达到了31。


发布时间:2022-08-12 13:01:40

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版权所有河北师范大学

冀ICP备18011017号-3

冀公网安备 13010802000630号

地址:河北省石家庄市南二环东路20号

邮编:050024