Pasquale Gabriele, Faria Junior Paulo E, Feng Shun, Collette Eloi, Watanabe Kenji, Taniguchi Takashi, Fabian Jaroslav, Kis Andras
Institute of Electrical and Microengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Nat Mater. 2025 Feb;24(2):212-218. doi: 10.1038/s41563-024-02067-9. Epub 2025 Jan 8.
Chirality, a basic property of symmetry breaking, is crucial for fields such as biology and physics. Recent advances in the study of chiral systems have stimulated interest in the discovery of symmetry-breaking states that enable exotic phenomena such as spontaneous gyrotropic order and superconductivity. Here we examine the interaction between light chirality and electron spins in indium selenide and study the effect of magnetic field on emerging tunnelling photocurrents at the Van Hove singularity. Although the effect is symmetric under linearly polarized light excitation, a non-symmetric signal emerges when the excitation is circularly polarized, making it possible to electrically detect light's chirality. Our study shows a negligible out-of-plane g-factor for few-layer indium selenide at the valence band edge, resulting in an unbalanced Zeeman splitting in hexagonal boron nitride spin bands. This finding allows us to measure the change in energy barrier height with exceptional resolution (~15 μeV). Furthermore, we confirm the long-standing theoretical prediction of spin-polarized hole accumulation in the flat valence band at increasing laser powers.
手性作为对称性破缺的一种基本属性，对于生物学和物理学等领域至关重要。手性系统研究的最新进展激发了人们对发现对称性破缺态的兴趣，这些态能够引发诸如自发旋光序和超导等奇异现象。在此，我们研究了硒化铟中光的手性与电子自旋之间的相互作用，并研究了磁场对范霍夫奇点处出现的隧穿光电流的影响。尽管该效应在线偏振光激发下是对称的，但当激发为圆偏振时会出现非对称信号，从而使得电检测光的手性成为可能。我们的研究表明，对于几层硒化铟，价带边缘的面外g因子可忽略不计，这导致六方氮化硼自旋带中的塞曼分裂不平衡。这一发现使我们能够以极高的分辨率（约15 μeV）测量能垒高度的变化。此外，我们证实了长期以来的理论预测，即在激光功率增加时，平带价带中会出现自旋极化的空穴积累。
