Homotopy-Theoretic Study &Atomic-Scale Observation of Vortex Domains in Hexagonal Manganites.
Essential structural properties of the non-trivial "string-wall-bounded" topological defects in hexagonal manganites are studied through homotopy group theory and spherical aberration-corrected scanning transmission electron microscopy. The appearance of a "string-wall-bounded" configuration in RMnO3 is shown to be strongly linked with the transformation of the degeneracy space. The defect core regions (~50 Å) mainly adopt the continuous U(1) symmetry of the high-temperature phase, which is essential for the formation and proliferation of vortices. Direct visualization of vortex strings at atomic scale provides insight into the mechanisms and macro-behavior of topological defects in crystalline materials.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
Jun
J
Li
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|National Institute of Clean-and-Low-Carbon Energy, Beijing 100209, China.
Fu-Kuo
FK
Chiang
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
Zhen
Z
Chen
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Chao
C
Ma
Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan.
Ming-Wen
MW
Chu
Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan.|Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
Cheng-Hsuan
CH
Chen
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Huanfang
H
Tian
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
Huaixin
H
Yang
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.|University of Chinese Academy of Sciences, Beijing 100049, China.|Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China.
Jianqi
J
Li