Dimensional evolution of spin correlations in the magnetic pyrochlore Yb2Ti2O7

作者：Ross K A^*; Yaraskavitch L R; Laver M; Gardner J S; Quilliam J A; Meng S; Kycia J B; Singh D K; Proffen Th; Dabkowska H A; Gaulin B D

来源：Physical Review B, 2011, 84(17): 174442.

DOI：10.1103/PhysRevB.84.174442

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.

• 出版日期2011-11-30
• 单位Los Alamos