NCTS (South)


DATE2011-04-20

TIME10:30

PLACERoom 815, New Physics Building, NTU

FIELDComputational Materials Research

SPEAKER Dr. Shigeki Onoda - Condensed Matter Theory Lab., RIKEN, Japan

TITLEChiral spin order and electromagnetic dynamics in one-dimensional multiferroic cuprates

ABSTRACTWe show by unbiased numerical calculations that the ferromagnetic nearest-neighbor exchange interaction stabilizes a vector spin chiral order against the quantum fluctuation in a frustrated spin-1/2 chain relevant to multiferroic cuprates, LiCu2O2 and LiCuVO4. Our semi-classical analyses including inter-chain couplings for LiCu2O2 resolve controversies on the helical magnetic structure and unveil the pseudo-Nambu-Goldstone modes as the origin of experimentally observed electromagnons.

[1] S. Furukawa, M. Sato, and S. Onoda, Phys. Rev. Lett. 105, 257205 (2010).