论文标题
沮丧的磁相互作用和CRA中的淬火自旋波动
Frustrated magnetic interactions and quenched spin fluctuations in CrAs
论文作者
论文摘要
在Helimagnets（CRAS，MNP）中发现压力诱导的超导性的发现引起了人们对理解复杂磁性与非常规超导性之间关系的极大兴趣。但是，驱动这些材料中异常双螺旋磁序的磁性和磁相互作用的性质尚不清楚。在这里，我们报告了在环境压力下CRAS单晶中磁激发的中子散射测量。我们的实验揭示了以低于7 MEV的伪甘蓝的伪造，揭示了大约150 MEV的旋转波激发，可以通过与最近的邻居交换相互作用的Heisenberg模型有效地描述。最令人惊讶的是，与丘脑和铁皮质体相比，旋转激发在很大程度上被淬灭，而光谱量主要保存在顺磁性状态下。我们的结果表明，Helimagnetic Order是由强烈沮丧的交换相互作用驱动的，Cras正处于巡回和相关诱导的局部状态的边缘，因此，这是高压调节性的，有利于超导性。
The discovery of pressure-induced superconductivity in helimagnets (CrAs, MnP) has attracted considerable interest in understanding the relationship between complex magnetism and unconventional superconductivity. However, the nature of the magnetism and magnetic interactions that drive the unusual double-helical magnetic order in these materials remains unclear. Here, we report neutron scattering measurements of magnetic excitations in CrAs single crystals at ambient pressure. Our experiments reveal well defined spin wave excitations up to about 150 meV with a pseudogap below 7 meV, which can be effectively described by the Heisenberg model with nearest neighbor exchange interactions. Most surprisingly, the spin excitations are largely quenched above the Neel temperature, in contrast to cuprates and iron pnictides where the spectral weight is mostly preserved in the paramagnetic state. Our results suggest that the helimagnetic order is driven by strongly frustrated exchange interactions, and that CrAs is at the verge of itinerant and correlation-induced localized states, which is therefore highly pressure-tunable and favorable for superconductivity.
