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arXiv 0901.0859cond-mat.str-el
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用NMR计算蓝铜矿1/3磁化平台的自旋组态

Spin Configuration in the 1/3 Magnetization Plateau of Azurite Determined by NMR

F. Aimo, S. Kramer, M. Klanjsek, M. Horvatic, C. Berthier, H. Kikuchi

摘要:

用高磁场$^{63,65}$ Cu NMR谱测定了蓝铜矿Cu $_3$(CO $_3$)$_2$(OH)$_2$的1/3磁化平台中的局部自旋极化。Cu 2(二聚体)位的超精细场的自旋部分被发现是场无关的、负的和强各向异性的,对应于$d$ -轨道中的全极化自旋的$\approx$ 10%。这接近于“量子”平台的预期构型,其中单重态在二聚体上稳定。然而,所观察到的非零自旋极化指向一些三重态混合物,由金刚石键$J_1$和$J_3$的强不对称性引起。

英文摘要:

High magnetic field $^{63,65}$Cu NMR spectra were used to determine the local spin polarization in the 1/3 magnetization plateau of azurite, Cu$_3$(CO$_3$)$_2$(OH)$_2$, which is a model system for the distorted diamond antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the Cu2 (dimer) sites is found to be field independent, negative and strongly anisotropic, corresponding to $\approx$10 % of fully polarized spin in a $d$-orbital. This is close to the expected configuration of the "quantum" plateau, where a singlet state is stabilized on the dimer. However, the observed non-zero spin polarization points to some triplet admixture, induced by strong asymmetry of the diamond bonds $J_1$ and $J_3$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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