论文标题
拓扑绝缘体超材料，具有巨大的圆形光藻效应
Topological Insulator Metamaterial with Giant Circular Photogalvanic Effect
论文作者
论文摘要
拓扑绝缘子电子性能最引人注目的表现之一是光电流方向对圆形极化光激发的螺旋性的依赖性。由表面狄拉克电子的自旋摩托明锁定的基础的螺旋依赖性光电量很弱且容易被大量贡献所掩盖。在这里，我们表明可以通过纳米结构来增强手性反应。 The tight confinement of electromagnetic fields in the resonant nanostructure enhances the photoexcitation of spin-polarized surface states of topological insulator Bi1.5Sb0.5Te1.8Se1.2, leading to an 11-fold increase of the circular photogalvanic effect and an unprecedented photocurrent dichroism (\r{ho}circ=0.87) at room temperature.结构设计对拓扑材料中的自旋传输的控制是超前无法识别的能力，它弥合了纳米光子学和自旋电子之间的差距，为开发极化敏感的光电探测器提供了新的机会。
One of the most striking manifestations of electronic properties of topological insulators is the dependence of the photocurrent direction on the helicity of circularly polarized optical excitation. The helicity dependent photocurrents, underpinned by spin-momentum locking of surface Dirac electrons, are weak and easily overshadowed by bulk contributions. Here we show that the chiral response can be enhanced by nanostructuring. The tight confinement of electromagnetic fields in the resonant nanostructure enhances the photoexcitation of spin-polarized surface states of topological insulator Bi1.5Sb0.5Te1.8Se1.2, leading to an 11-fold increase of the circular photogalvanic effect and an unprecedented photocurrent dichroism (\r{ho}circ=0.87) at room temperature. The control of spin-transport in topological materials by structural design is a previously unrecognised ability of metamaterials that bridges the gap between nanophotonics and spin-electronics, providing new opportunities for developing polarization sensitive photodetectors.
