It was previously believed that the Bloch electronic states of non-magnetic materials with inversion symmetry cannot have finite spin polarizations. However, since the seminal work by Zhang et al. (Nat. Phys. 10, 387–393 (2014)) on local spin polarizations of Bloch states in non-magnetic, centrosymmetric materials, the scope of spintronics has been significantly broadened. Here, we show, using a framework that is universally applicable independent of whether hidden spin polarizations are small (e.g., diamond, Si, Ge and GaAs) or large (e.g., MoS₂ and WSe₂), that the corresponding quantity arising from orbital—instead of spin—degrees of freedom, the hidden orbital polarization is (i) much more abundant in nature since it exists even without spin–orbit coupling and (ii) more fundamental since the interband matrix elements of the site-dependent orbital angular momentum operator determine the hidden spin polarization. We predict that the hidden spin polarization of transition metal dichalcogenides is reduced significantly upon compression. We suggest experimental signatures of hidden orbital polarization from photoemission spectroscopies and demonstrate that the current-induced hidden orbital polarization may play a far more important role than its spin counterpart in antiferromagnetic information technology by calculating the current-driven antiferromagnetism in compressed silicon.

先前认为具有反对称性的非磁性材料的Bloch电子态不能具有有限的自旋极化。然而，由于张等人的开创性工作。（纳特。物理学。在非磁性中心对称材料布洛赫状态的局部自旋极化10，387-393（2014）），自旋电子学的范围已显著扩大。在这里，我们显示了一个普遍适用的框架，而与隐藏的自旋极化是小（例如，金刚石，Si，Ge和GaAs）还是大（例如，MoS ₂和WSe ₂）无关，其相应的量是由轨道引起的（而不是自旋）自由度，隐藏的轨道极化（i）本质上要丰富得多，因为即使没有自旋-轨道耦合它也存在，并且（ii）更基本，因为取决于位置的轨道角动量算符的带间矩阵元素确定了隐藏的自旋极化。我们预测过渡金属二卤化碳的隐藏自旋极化在压缩后会显着降低。我们建议从光发射光谱学中获得隐藏轨道极化的实验特征，并通过计算压缩硅中的电流驱动反铁磁性，证明电流诱导的隐藏轨道极化在反铁磁信息技术中起着比自旋对应更重要的作用。