Anisotropic spin freezing in lightly-doped LaSrCuO

Matsuda, Masaaki; Fujita, Masaki*; Takeda, Masayasu  ; Yamada, Kazuyoshi*; Kakurai, Kazuhisa

Polarized neutron scattering is an important tool to clarify the existence of chirality. Furthermore, it also gives useful information on magnetic anisotropy of the spin fluctuations in the diagonal incommensurate phase. We performed polarized neutron scattering experiments in lightly-doped LaSrCuO. The results showed that the chiral terms are almost negligible, indicating that there is no chirality or that the two chirality domains are equally populated. The diagonal terms originate from the magnetic anisotropy in the antiferromagnetically ordered phase. It was found that the spins lie almost in the CuO plane although a finite out-of-plane component was observed. It was also found that there exists a small anisotropy in the CuO plane and the spin component is larger along the b axis, suggesting the remnant of anisotropy in pure LaCuO.