Title: Spin polarized enantio-sensitive multipolar photoelectron currents Show Chinese title

Title: 自旋极化手性敏感的多极光电流

Abstract: Photoelectron circular dichroism (PECD) manifests as a forward-backward asymmetry of electron emission in the direction orthogonal to the light polarization plane via one-photon ionization of chiral molecules with circularly polarized light. Multi-polar `PECD' currents, i.e., currents resolved along multiple directions, have also been predicted using two mutually-orthogonal linearly polarized light with carrier frequencies $\omega$ and $2\omega$. These currents arise from the interference between the one- and two-photon transitions. Here, we will show that photoelectron spin detection reveals enantio-sensitive multi-polar currents already in the one-photon regime since the two axes can be marked by the photoelectron momentum and spin-detection axis. Specifically, we consider one-photon ionization of an isotropic ensemble of randomly oriented chiral molecules via circularly polarized light and show that the resulting spin-resolved current has three components whose magnitudes are comparable and can be larger than PECD: (i) a spin-polarization vortex in the plane of light polarization that rotates in opposite directions for opposite enantiomers, (ii) either a spin-sink or source in the plane of light polarization for opposite enantiomers, and (iii) a spin analog of photoelectron vortex dichroism (\href{https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.233201}{Phys. Rev. Lett. \textbf{129}, 233201, 2022}) wherein the detected photoelectron spin encodes molecular chirality. Show Chinese abstract

Abstract: 光电子圆二色性（PECD）表现为手性分子通过圆偏振光单光子电离时，在垂直于光偏振面的方向上电子发射的前向-后向不对称性。 此外，使用两个相互正交的线偏振光（载波频率分别为$\omega$和$2\omega$），还预测了多极“PECD”电流，即沿多个方向分解的电流。 这些电流源于一光子跃迁和两光子跃迁之间的干涉。 在这里，我们将展示光电子自旋检测在单光子情况下即可揭示手性敏感的多极电流，因为这两个轴可以通过光电子动量和自旋检测轴来标记。 具体来说，我们考虑通过圆偏振光对手性分子的各向同性集合进行单光子电离，结果显示由此产生的自旋分辨电流有三个分量，其幅度相当且可能大于PECD：（i）在光偏振平面内的自旋极化涡流，对映异构体相反时旋转方向相反；（ii）对映异构体相反时在光偏振平面内表现为自旋汇或源；（iii）光电子涡旋二色性的自旋类似物 (\href{https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.233201}{物理评论快报\textbf{129}, 233201, 2022})，其中检测到的光电子自旋编码分子的手性。