Dimensional evolution of spin correlations in the magnetic pyrochlore Yb2Ti2O7
Dimensional evolution of spin correlations in the magnetic pyrochlore Yb2Ti2O7
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DOI：
10.1103/physrevb.84.174442
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发表时间：
2011-11-30
影响因子：
3.7
通讯作者：
Gaulin, B. D.
中科院分区：
文献类型：
--
作者：
Ross, K. A.;Yaraskavitch, L. R.;Gaulin, B. D.
焦绿石材料Yb2Ti2O7在低温立方晶格环境中表现出意想不到的准二维(2D)磁关联，然后在T=265mK以下进入奇异的无序基态。我们报道了二维自旋关联在空间和时间上的热演化的中子散射测量。短程三维(3D)自旋关联在400mK以下发展，同时伴随着类似于0.2 meV以下的准弹性(QE)散射的抑制。它们显示了一种缓慢波动的基态，在Kagome-三角形-Kagome(KTK)堆栈中，自旋短距离地关联在沿[111]的Kagome-三角形-Kagome堆栈中，在较高的温度下演化为孤立的Kagome自旋星。此外，低温比热结果表明，样品依赖于假定的转变温度，其界限为265mK，这一点我们在最近的平均场理论分析的背景下进行了讨论。
The pyrochlore material Yb2Ti2O7 displays unexpected quasi-two-dimensional (2D) magnetic correlations within a cubic lattice environment at low temperatures, before entering an exotic disordered ground state below T = 265 mK. We report neutron scattering measurements of the thermal evolution of the 2D spin correlations in space and time. Short-range three-dimensional (3D) spin correlations develop below 400 mK, accompanied by a suppression in the quasielastic (QE) scattering below similar to 0.2 meV. These show a slowly fluctuating ground state with spins correlated over short distances within a kagome-triangular-kagome (KTK) stack along [111], which evolves to isolated kagome spin stars at higher temperatures. Furthermore, low-temperature specific heat results indicate a sample dependence to the putative transition temperature that is bounded by 265 mK, which we discuss in the context of recent mean field theoretical analysis.