WSe₂-NiPS₃磁性范德瓦尔斯异质结构中的光谱可调控自旋极化光电流
Spectrally Programmable Spin-Polarized Photocurrents in WSe$_2$-NiPS$_3$ Magnetic van der Waals Heterostructures
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中文总结 AI 辅助
该研究构建WSe₂-NiPS₃磁性范德瓦尔斯异质结构，利用光谱调谐实现无磁场的高自旋极化光电流产生，为光自旋电子器件提供了新平台。
中文摘要 AI 辅助
半导体中自旋极化电流的高效产生与调控是自旋电子学的核心挑战，尤其受限于阻抗不匹配，且需依赖磁场或铁磁接触。本文引入一种基于范德瓦尔斯异质结构的光谱可调控自旋输运材料平台，该异质结构由反铁磁半导体NiPS₃与WSe₂复合而成。在p-n二极管结构中，圆偏振激发产生显著的光电导共振，其自旋极化率在奈尔温度附近可达80%，室温下仍保持30%。值得注意的是，选定的光谱带在磁相变过程中保留其极化符号，证明了鲁棒的、受光谱保护的自旋极化电流产生。偏振分辨光电流测量揭示了主导的圆注入电流机制，证实了自旋极化载流子输运。第一性原理计算表明，外加电场诱导界面杂化与自旋层锁定，产生局域对称性破缺并增强光吸收，同时保持整体时间反演对称性。这些结果确立了激发的光谱调谐作为自旋输运的新调控旋钮，可实现无磁场或极化开关的自旋电流产生。本研究将磁性范德瓦尔斯异质结构确立为光自旋电子功能及光谱可调控自旋电子器件的通用平台。
英文摘要
Efficient generation and control of spin-polarized currents in semiconductors remain central challenges for spin-based electronics, particularly due to impedance mismatch and the reliance on magnetic fields or ferromagnetic contacts. Here, we introduce a materials platform for spectrally programmable spin transport based on a van der Waals heterostructure combining the antiferromagnetic semiconductor NiPS$_3$ with WSe$_2$. In a p-n diode architecture, circularly polarized excitation produces pronounced photoconductive resonances with spin polarization reaching 80% near the Neel temperature and persisting at 30% at room temperature. Remarkably, selected spectral bands retain their polarization sign across the magnetic phase transition, evidencing robust, spectrally protected spin-polarized current generation. Polarization-resolved photogalvanic measurements reveal a dominant circular injection-current mechanism, confirming spin-polarized carrier transport. First-principles calculations show that an applied electric field induces interfacial hybridization and spin-layer locking, giving rise to localized symmetry breaking and enhanced optical absorption while preserving global time-reversal symmetry. These results establish spectral tuning of excitation as a new control knob for spin transport, enabling spin-current generation without magnetic fields or polarization switching. Our findings position magnetic van der Waals heterostructures as a versatile platform for opto-spintronic functionality and spectrally programmable spintronic devices.
