By means of spin current, the flow of spin angular momentum, we find a regime of "spin treacle" in a frustrated magnetic system. To establish its existence, we have performed spin transport measurements in nanometer-scale spin glasses. At temperatures high enough that the magnetic moments fluctuate at high frequencies, the spin Hall angle, the conversion yield between spin current and charge current, is independent of temperature. The spin Hall angle starts to decrease at a certain temperature $T^{*}$ and completely vanishes at a lower temperature. We argue that the latter corresponds to the spin freezing temperature $T_{\rm f}$ of the nanometer-scale spin glass, where the direction of conduction electron spin is randomized by the exchange coupling with the localized moments. The present experiment \textit{quantitatively} verifies the existence of a distinct "spin treacle" between $T_{\rm f}$ and $T^{*}$. We have also quantified a time scale of fluctuation of local magnetic moments in the spin treacle from the spin relaxation time of conduction electrons.
Magnetic states and ferromagnetic resonance in geometrically frustrated arrays of multilayer ferromagnetic nanoparticles ordered on triangular lattices
Skyrmion instabilities and distorted spiral states in a frustrated chiral magnet
磁skyrmion是最近产生的兴趣作为候选人的未来自旋电子器件的skyrmion小尺寸，增强的拓扑稳定性，和/或相互作用的粒子状的拓扑激发。在这里，我们研究孤立的skyrmions在一个沮丧的手征磁铁与竞争Dzyaloshinskiii-Moriya和沮丧的交换相互作用的性质。我们表明，skyrmion的大小急剧下降，即使是小值的竞争稳定机制。Skyrmion相互作用仍然吸引，因为是固有的挫折skyrmion，但值的Dzyaloshinskii常数调节的相互作用潜力的最小值的数量。此外，所构建的相图手性helimagnet包含一个扭曲的螺旋状态，可以被认为是螺旋和圆锥形的一维调制之间的缓冲区。所阐述的概念可以进一步增强自旋电子器件的功能。特别是，相对于锥形状态的skyrmions的受控不稳定性允许获得双分子状结构。此外，我们的结果提供了物理洞察的手征状态的磁系统，例如，在MnSi $_{1-x}$ Ge $_x$中。
