论文标题
从三维拓扑绝缘子bi2te3发出的手性terahertz波的生成和操纵
Generation and manipulation of chiral terahertz waves emitted from the three-dimensional topological insulator Bi2Te3
论文作者
论文摘要
在源上弹性极化的宽带Terahertz波的任意操纵在扩展真实应用,例如成像,信息加密和对Terahertz非线性现象的全面相干控制等实际应用中具有很大的潜力。具有独特的旋转摩托锁定表面状态的拓扑绝缘子已经在Terahertz发射,检测和调制中表现出非常有前途的前景,这可能为未来的基于芯片拓扑绝缘子的Terahertz Systems奠定了基础。然而,尚未探索极化形状的幅度,其幅度和电场矢量方向的随意操纵时间演变的规定的terahertz发射尚未探索。在这里,我们系统地研究了由飞秒激光脉冲驱动的拓扑绝缘体BI2TE3纳米膜的Terahertz辐射,并成功地实现了具有可控的手性手性,椭圆性,椭圆性和原理轴的有效性手性Terahertz波的产生。手性terahertz波的方便工程通过光钙效应引起的光电流来解释,而线性偏振的Terahertz波源自线性光钙效应引起的移位电流。我们认为,我们的作品不仅有助于进一步理解飞秒连贯的连贯控制在光结合相互作用中的超快自旋电流,而且还提供了一种有效的方法来产生自旋极化的Terahertz波,并加速了扭曲源头上Terahertz波的增殖。
Arbitrary manipulation of broadband terahertz waves with flexible polarization shaping at the source has great potential in expanding real applications such as imaging, information encryption, and all-optically coherent control of terahertz nonlinear phenomena. Topological insulators featuring unique spin-momentum locked surface state have already exhibited very promising prospects in terahertz emission, detection and modulation, which may lay a foundation for future on-chip topological insulator-based terahertz systems. However, polarization shaped terahertz emission with prescribed manners of arbitrarily manipulated temporal evolution of the amplitude and electric-field vector direction based on topological insulators have not yet been explored. Here we systematically investigated the terahertz radiation from topological insulator Bi2Te3 nanofilms driven by femtosecond laser pulses, and successfully realized the generation of efficient chiral terahertz waves with controllable chirality, ellipticity, and principle axis. The convenient engineering of the chiral terahertz waves was interpreted by photogalvanic effect induced photocurrent, while the linearly polarized terahertz waves originated from linear photogalvanic effect induced shift currents. We believe our works not only help further understanding femtosecond coherent control of ultrafast spin currents in light-matter interaction but also provide an effective way to generate spin-polarized terahertz waves and accelerate the proliferation of twisting the terahertz waves at the source.