[LA-SiGMA] LASiGMA Seminar - Dr. Sang-Wook Cheong, Wednesday May 8, 3:30 p.m.

[sjlee at cct.lsu.edu]

Dear All,

Dr. Sang Wook Cheong, of Rutgers University, will be giving a seminar  
Wednesday, May 8, at 3:30 pm in 338 Johnston Hall at Louisiana State  
University. The title of his talk is "Multiferroic Vortices: Materials  
Science, Particle Physics & Cosmology."

Abstract:
Hexagonal REMnO3 (RE= rare earths) with RE=Ho-Lu, Y, and Sc, is an  
improper ferroelectric where the size mismatch between RE and Mn  
induces a trimerization-type structural phase transition, and this  
structural transition leads to three structural domains, each of which  
can support two directions of ferroelectric polarization. We reported  
that domains in h-REMnO3 meet in cloverleaf arrangements that cycle  
through all six domain configurations. Occurring in pairs, the  
cloverleafs can be viewed as vortices and antivortices, in which the  
cycle of domain configurations is reversed. Vortices and antivortices  
are topological defects: even in a strong electric field they won’t  
annihilate. These ferroelectric vortices/antivortices are found to be  
associated with intriguing collective magnetism at domain walls,  
reflecting the multiferroic nature of vortices.

Dr. Sang-Wook Cheong has made founding contributions to the research  
field of enhanced physical functionalities in complex materials  
originating from collective correlations such as colossal  
magnetoresistive and colossal magnetoelectric effects in complex  
oxides. He has also made pivotal contributions to mezoscopic phase  
complexity issues in functional materials, including the nanoscale  
charge stripe formation and mesoscopic electronic phase separation in  
mixed valent transition metal oxides and the formation of topological  
vortex domains in multiferroics that turns out to be synergistically  
relevant to mathematics (graph theory) and even cosmology. He has  
published more than 600 scientific papers, and the total citation is  
more than 32,000 (four papers cited more than 1000 times, and his  
h-index is 89). His educational background includes mathematics in  
college, string theory (about three years) in graduate school, and  
solid state physics for PhD. He has worked at Los Alamos National  
Laboratory, AT&T Bell Laboratories, and Rutgers Center for Emergent  
Materials (RCEM), Rutgers. He is currently the director of RCEM, a  
Board of Governors Professor at Rutgers, and a Distinguished Professor  
at Postech, Korea. His work on complex oxides has been recognized  
through various prizes, including the 2007 Hoam Prize sponsored by  
Samsung, the KBS 2009 Global Korean Award, and the 2010 James C.  
McGroddy Prize for New Materials sponsored by IBM.

The seminar will be a live broadcast from Louisiana State University,
and can be viewed live at the sites listed below:

UNO - Liberal Arts Building 234
Xavier - Qatar Pavilion Conference Room 226
Southern University - JB Moore Hall, Room 211
LATech - PML 1015, Center for Instructional Technology, at the Wyly Tower

The seminar will also be accessible via adobe connect by clicking on
following link: https://connect.lsu.edu/la-sigma/

Please let me know if you have any questions.

Regards,

Shelley Lee
Project Coordinator
225-578-0465

























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