论文标题
量子液体的磁八杆散射
Neutron scattering by magnetic octupoles of a quantum liquid
论文作者
论文摘要
中子散射是研究磁性结构和动力学的强大工具，得益于精确建立的理论框架。中子偶极矩通过其磁场中的材料中的电子相互作用，这些磁场可以具有自旋和轨道的起源。然而，在大多数实验研究的情况下，单个自由度在偶极子近似中得到很好的描述，有时还伴随着多极扩展的进一步术语，通常是对偶极子形式的较小校正。在这里，我们报告了一个主要由磁性八杆衍射的中子的独特示例。这种异常的情况是在量子自旋冰中产生的，在该量子冰中，电子波函数在相关性的效果下基本上变为八极极。在中子散射中带有特定的实验签名的这种新型量子自旋液体的发现是显着的，因为众所周知，这些物质的局部状态很难检测到。
Neutron scattering is a powerful tool to study magnetic structures and dynamics, benefiting from a precisely established theoretical framework. The neutron dipole moment interacts with electrons in materials via their magnetic field, which can have spin and orbital origins. Yet in most experimentally studied cases the individual degrees of freedom are well described within the dipole approximation, sometimes accompanied by further terms of a multipolar expansion that usually act as minor corrections to the dipole form factor. Here we report a unique example of neutrons diffracted mainly by magnetic octupoles. This unusual situation arises in a quantum spin ice where the electronic wavefunction becomes essentially octupolar under the effect of correlations. The discovery of such a new type of quantum spin liquid that comes with a specific experimental signature in neutron scattering is remarkable, because these topical states of matter are notoriously difficult to detect.
