论文标题
旋转 - 瓦利半米的动力自旋敏感性
Dynamical spin susceptibility of spin-valley half-metal
论文作者
论文摘要
几年前，我们从理论上预测，在嵌套费米表面的系统中，自旋 - 瓦利半金属的能量低于自旋密度波状态。在本文中，我们提出了一种实验区分这些阶段的可能方法。我们计算了久保形式框架中两个状态的动力自旋敏感性张量。讨论的阶段具有不同的频段：旋转 - 瓦利半金属中的四个频带，在自旋密度波中只有两个频段。因此，它们作为频率的功能具有不同数量的峰值的敏感性。此外，自旋谷半金属没有旋转对称性，因此，通常，易感性张量的非对角线成分非零。旋转密度波遵守易感性张量的稳健旋转对称性和偏对分量为零。在非弹性中子散射的实验中可以观察到这些特征。
A few years ago we predicted theoretically that in systems with nesting of the Fermi surface the spin-valley half-metal has lower energy than the spin density wave state. In this paper we suggest a possible way to distinguish these phases experimentally. We calculate dynamical spin susceptibility tensor for both states in the framework of the Kubo formalism. Discussed phases have different numbers of the bands: four bands in the spin-valley half-metal and only two bands in the spin density wave. Therefore, their susceptibilities, as functions of frequency, have different number of peaks. Besides, the spin-valley half-metal does not have rotational symmetry, thus, in general the off-diagonal components of susceptibility tensor are non-zero. The spin density wave obeys robust rotational symmetry and off-diagonal components of the susceptibility tensor are zero. These characteristic features can be observed in experiments with inelastic neutron scattering.
