近日，美国科罗拉多大学博尔德分校Matthew C. Beard团队研究了用太赫兹辐射观察超快反手性诱导的自旋选择性。2025年11月6日出版的《科学》杂志发表了这项成果。

手性诱导自旋选择性（CISS）现象是结构手性、电子自旋取向和电荷电流相互作用的结果。诸如磁电阻之类的稳态观测对控制自旋-电荷相互转换的时间尺度提供了很少的见解，并且经常将界面和体现象混为一谈。相反，逆CISS涉及自旋到电荷电流的转换。

利用太赫兹（THz）发射光谱，研究组以皮秒时间分辨率直接测量了逆CISS引起的超快电荷电流。太赫兹辐射的极性和极化分析映射了自旋注入后的感应电荷电流方向。研究组发现沿自旋方向产生的电荷电流随着立体化学构型的改变而改变方向。这些观察结果直接证明了手性系统中自旋和电荷电流之间的内在耦合，为其基本动力学提供了关键见解。

附：英文原文

Title: Ultrafast inverse chirality-induced spin selectivity observed by THz emission

Author: Yifan Dong, Aeron McConnell, Matthew P. Hautzinger, Md Azimul Haque, Andrew H. Comstock, Pius M. Theiler, Joseph M. Luther, Peter C. Sercel, Dali Sun, Matthew C. Beard

Issue&Volume: 2025-11-06

Abstract: Chirality-induced spin selectivity (CISS) phenomena arise from an interplay among structural chirality, electron spin orientation, and charge current. Steady-state observations such as magnetoresistance offer little insight into the timescales that govern the spin-charge interconversion and often conflate interfacial and bulk phenomena. By contrast, inverse CISS involves the conversion of spin to a charge current. Using terahertz (THz) emission spectroscopy, we directly measured an ultrafast charge current due to inverse CISS with picosecond time resolution. Polarity and polarization analysis of the THz emission map the induced charge current direction upon spin injection. We found that a charge current is generated along the spin orientation that changes direction with stereochemical configuration. These observations directly demonstrate the inherent coupling between spin and charge currents in chiral systems, offering key insights into their fundamental dynamics.

DOI: ady4885

Source: https://www.science.org/doi/10.1126/science.ady4885