Realization of a three-dimensional spin-anisotropic harmonic honeycomb iridate
Realization of a three-dimensional spin-anisotropic harmonic honeycomb iridate
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DOI：
10.1038/ncomms5203
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发表时间：
2014-06-01
影响因子：
16.6
通讯作者：
Analytis, James G.
中科院分区：
文献类型：
--
作者：
Modic, K. A.;Smidt, Tess E.;Analytis, James G.
自旋和轨道量子数在莫特绝缘体的物理学中起着关键作用，但在大多数系统中，它们只是通过泡利不相容原理和库仑相互作用间接联系起来。铱基氧化物（铱酸盐）直接引入强的自旋轨道耦合，使得这些数被叠加在一起，莫特物理获得强的轨道特征。在层状蜂窝状虹彩中，这被认为会产生高度自旋各向异性的磁相互作用，将自旋耦合到给定的空间交换方向，并导致强烈的受抑磁性。在这里，我们报告了一个新的铱酸盐结构，具有相同的局部连接的层状蜂窝状结构，并表现出惊人的证据，高度自旋各向异性交换。这种材料的基本结构单元表明，可能存在一种新的三维结构家族，即“谐波蜂窝”铱酸盐，本化合物是其中的第一个例子。
Spin and orbital quantum numbers play a key role in the physics of Mott insulators, but in most systems they are connected only indirectly-via the Pauli exclusion principle and the Coulomb interaction. Iridium-based oxides (iridates) introduce strong spin-orbit coupling directly, such that these numbers become entwined together and the Mott physics attains a strong orbital character. In the layered honeycomb iridates this is thought to generate highly spin-anisotropic magnetic interactions, coupling the spin to a given spatial direction of exchange and leading to strongly frustrated magnetism. Here we report a new iridate structure that has the same local connectivity as the layered honeycomb and exhibits striking evidence for highly spin-anisotropic exchange. The basic structural units of this material suggest that a new family of three-dimensional structures could exist, the 'harmonic honeycomb' iridates, of which the present compound is the first example.