Chirality or handedness distinguishes an object from its mirror images, such as the spread thumb, index finger, and middle finger of the right and left hand. In mathematics, it is described by the outer product of three vectors that obey a right-hand vs. left-hand rule. The chirality of ground state magnetic textures defined by the vectors of magnetization, its gradient, and an electric field from broken inversion symmetry can be fixed by a strong relativistic spin–orbit interaction. This review focuses on the chirality observed in the excited states of the magnetic order, dielectrics, and conductors that hold transverse spins when they are evanescent. Even without any relativistic effect, the transverse spin of the evanescent waves is locked to the momentum and the surface normal of their propagation plane. This chirality thereby acts as a generalized spin–orbit interaction, which leads to the discovery of various chiral interactions between magnetic, phononic, electronic, photonic, and plasmonic excitations in spintronics that mediate the excitation of quasiparticles into a single direction, leading to phenomena such as chiral spin and phonon pumping, chiral spin Seebeck, spin skin, magnonic trap, magnon Doppler, chiral magnon damping, and spin diode effects. Intriguing analogies with electric counterparts in the nano-optics and plasmonics exist. After a brief review of the concepts of chirality that characterize the ground state chiral magnetic textures and chirally coupled magnets in spintronics, we turn to the chiral phenomena of excited states. We present a unified electrodynamic picture for dynamical chirality in spintronics in terms of generalized spin–orbit interaction and compare it with that in nano-optics and plasmonics. Based on the general theory, we subsequently review the theoretical progress and experimental evidence of chiral interaction, as well as the near-field transfer of the transverse spins, between various excitations in magnetic, photonic, electronic and phononic nanostructures at GHz time scales. We provide a perspective for future research before concluding this article.

手性或手性将物体与其镜像区分开来，例如左右手张开的拇指、食指和中指。在数学中，它由遵守右手法则与左手法则的三个向量的外积来描述。由磁化矢量、磁化梯度和反演对称性破缺产生的电场定义的基态磁结构的手性可以通过强相对论自旋轨道相互作用来固定。这篇综述侧重于在激发态中观察到的手性磁序、电介质和导体在它们消失时保持横向自旋。即使没有任何相对论效应，倏逝波的横向自旋也被锁定在其传播平面的动量和表面法线。因此，这种手性作为一种广义的自旋轨道相互作用，导致发现自旋电子学中磁、声子、电子、光子和等离子体激发之间的各种手性相互作用，这些相互作用将准粒子的激发调解到一个方向，导致这样的现象作为手性自旋和声子泵浦、手性自旋塞贝克、自旋皮肤、磁子陷阱、磁子多普勒、手性磁子阻尼和自旋二极管效应。存在与纳米光学和等离子体中的电子对应物的有趣类比。在简要回顾了自旋电子学中表征基态手征磁结构和手征耦合磁体的手征概念之后，我们转向激发态的手征现象。我们根据广义自旋轨道相互作用提出了自旋电子学中动态手性的统一电动力学图，并将其与纳米光学和等离子体学中的图进行了比较。基于一般理论，我们随后回顾了 GHz 时间尺度的磁、光子、电子和声子纳米结构中各种激发之间手性相互作用的理论进展和实验证据，以及横向自旋的近场转移。在结束本文之前，我们为未来的研究提供了一个视角。