Correlation between spin helicity and an electric polarization vector in quantum-spin chain magnet LiCu2O2.
Measurements of polarized neutron scattering were performed on a S=1/2 chain multiferroic LiCu2O2. In the ferroelectric ground state with the spontaneous polarization along the c axis, the existence of transverse spiral spin component in the bc plane was confirmed. When the direction of electric polarization is reversed, the vector spin chirality as defined by C_(ij)=S_(i)xS_(j) (i and j being the neighboring spin sites) is observed to be reversed, indicating that the spin-current model or the inverse Dzyaloshinskii-Moriya mechanism is applicable even to this e_(g)-electron quantum-spin system. Differential scattering intensity of polarized neutrons shows a large discrepancy from that expected for the classical-spin bc-cycloidal structure, implying the effect of large quantum fluctuation.
Seki
S
S
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Yamasaki
Y
Y
Soda
M
M
Matsuura
M
M
Hirota
K
K
Tokura
Y
Y